osns - diffraction from magnetic materials - diffrac… · diffraction from magnetic materials....
TRANSCRIPT
I N S T I T U T L A U E L A N G E V I N
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Navid Qureshi
Diffraction from magnetic materials
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
H. Rietveld presents a least-squares program
able to refine crystal and magnetic structures
J. Rodríguez Carvajal presents the FullProf
packagePublications
Year
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
Methods and computing programs
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
Multiferroics
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
Superconductors
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
Nanoparticles
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
MotivationImpact of magnetic neutron scattering
correlated with
‣ availability of computing tools
‣ relevant topics in new materials
Order phenomena in manganites
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Outline
‣ Reminder: Nuclear scattering scattering amplitude, Fourier transform
‣ Magnetic scattering scattering potential, directional dependence
‣ Magnetic structures Ferro, antiferro, cycloids, helices, …
‣ Scattering from a unit cell Magnetic structure factor, interaction vector
‣ Experimental procedure
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Conventions for this lectureWave vector and scattering vector
: initial wavevector
: final wavevector
: momentum transfer, scattering vector
: reciprocal lattice vector
Elastic scattering:
kf<latexit sha1_base64="B7J8YulRjkgvkKb/1iea7956Y20=">AAAB83icbVDLSsNAFL2pr1pfVZduBovgQkqigi4LblxWsA9oQplMb9qhk0mYmQgl9DfcuFDErT/jzr9x2mahrQcGDufcyz1zwlRwbVz32ymtrW9sbpW3Kzu7e/sH1cOjtk4yxbDFEpGobkg1Ci6xZbgR2E0V0jgU2AnHdzO/84RK80Q+mkmKQUyHkkecUWMl34+pGYVRPp72o3615tbdOcgq8QpSgwLNfvXLHyQsi1EaJqjWPc9NTZBTZTgTOK34mcaUsjEdYs9SSWPUQT7PPCVnVhmQKFH2SUPm6u+NnMZaT+LQTs4y6mVvJv7n9TIT3QY5l2lmULLFoSgTxCRkVgAZcIXMiIkllClusxI2oooyY2uq2BK85S+vkvZl3buqew/XtcZFUUcZTuAUzsGDG2jAPTShBQxSeIZXeHMy58V5dz4WoyWn2DmGP3A+fwBhN5HV</latexit>
ki<latexit sha1_base64="/13hgp5wwDC3KNNbVjc6HKIMtB0=">AAAB83icbVDLSsNAFL2pr1pfVZduBovgQkqigi4LblxWsA9oQplMb9qhk0mYmQgl9DfcuFDErT/jzr9x2mahrQcGDufcyz1zwlRwbVz32ymtrW9sbpW3Kzu7e/sH1cOjtk4yxbDFEpGobkg1Ci6xZbgR2E0V0jgU2AnHdzO/84RK80Q+mkmKQUyHkkecUWMl34+pGYVRPp72eb9ac+vuHGSVeAWpQYFmv/rlDxKWxSgNE1TrnuemJsipMpwJnFb8TGNK2ZgOsWeppDHqIJ9nnpIzqwxIlCj7pCFz9fdGTmOtJ3FoJ2cZ9bI3E//zepmJboOcyzQzKNniUJQJYhIyK4AMuEJmxMQSyhS3WQkbUUWZsTVVbAne8pdXSfuy7l3VvYfrWuOiqKMMJ3AK5+DBDTTgHprQAgYpPMMrvDmZ8+K8Ox+L0ZJT7BzDHzifP2XDkdg=</latexit>
k<latexit sha1_base64="PhXbyvGIO65nFp2zHvXvHjgxBz4=">AAAB8XicbVBNS8NAFHypX7V+VT16WSyCBymJCnosePFYwdZiG8pmu2mXbjZh90Uoof/CiwdFvPpvvPlv3LQ5aOvAwjDzHjtvgkQKg6777ZRWVtfWN8qbla3tnd296v5B28SpZrzFYhnrTkANl0LxFgqUvJNoTqNA8odgfJP7D09cGxGre5wk3I/oUIlQMIpWeuxFFEdBmI2n/WrNrbszkGXiFaQGBZr96ldvELM04gqZpMZ0PTdBP6MaBZN8WumlhieUjemQdy1VNOLGz2aJp+TEKgMSxto+hWSm/t7IaGTMJArsZJ7QLHq5+J/XTTG89jOhkhS5YvOPwlQSjEl+PhkIzRnKiSWUaWGzEjaimjK0JVVsCd7iycukfV73Lure3WWtcVbUUYYjOIZT8OAKGnALTWgBAwXP8ApvjnFenHfnYz5acoqdQ/gD5/MH49aQ/A==</latexit>
G<latexit sha1_base64="mF8hcLEUKb0JTMp0GFUPovWfIRA=">AAAB8XicbVDLSgMxFL1TX7W+qi7dBIvgQsqMCrosuNBlBfvAtpRMeqcNzWSGJCOUoX/hxoUibv0bd/6NmXYW2nogcDjnXnLu8WPBtXHdb6ewsrq2vlHcLG1t7+zulfcPmjpKFMMGi0Sk2j7VKLjEhuFGYDtWSENfYMsf32R+6wmV5pF8MJMYeyEdSh5wRo2VHrshNSM/SG+n/XLFrbozkGXi5aQCOer98ld3ELEkRGmYoFp3PDc2vZQqw5nAaambaIwpG9MhdiyVNETdS2eJp+TEKgMSRMo+achM/b2R0lDrSejbySyhXvQy8T+vk5jgupdyGScGJZt/FCSCmIhk55MBV8iMmFhCmeI2K2EjqigztqSSLcFbPHmZNM+r3kXVu7+s1M7yOopwBMdwCh5cQQ3uoA4NYCDhGV7hzdHOi/PufMxHC06+cwh/4Hz+AK0ikNg=</latexit>
|ki| = |kf | = k<latexit sha1_base64="F4YxrzJhIIQkOJ4n8XV45PICf8Y=">AAACD3icbVDLSsNAFL3xWesr6tLNYFFcSElU0I1QcOOygn1AG8JkOmmHTh7MTISS9g/c+CtuXCji1q07/8ZJmkVtPXDhcM693HuPF3MmlWX9GEvLK6tr66WN8ubW9s6uubfflFEiCG2QiEei7WFJOQtpQzHFaTsWFAcepy1veJv5rUcqJIvCBzWKqRPgfsh8RrDSkmuejLsBVgPPT4cTl6ExutE1I/m5NHTNilW1cqBFYhekAgXqrvnd7UUkCWioCMdSdmwrVk6KhWKE00m5m0gaYzLEfdrRNMQBlU6a/zNBx1rpIT8SukKFcnV2IsWBlKPA053ZpXLey8T/vE6i/GsnZWGcKBqS6SI/4UhFKAsH9ZigRPGRJpgIpm9FZIAFJkpHWNYh2PMvL5LmedW+qNr3l5XaWRFHCQ7hCE7BhiuowR3UoQEEnuAF3uDdeDZejQ/jc9q6ZBQzB/AHxtcvtrSbuA==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringScattering cross section
dn|{z}ns�1
= �|{z}ncm�2s�1
· d⌦|{z}1
·�(✓,')| {z }cm2
<latexit sha1_base64="lZypFLWk2gl4ol98oaj130phTMQ=">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</latexit>
𝜎 has the unit of a surface
usually in barns = 10-24 cm2
Number of neutrons n detected in solid angle ⌦<latexit sha1_base64="wmuaksdsi8WKe/JAndUeSpkLXXc=">AAAB7XicbVDLSgNBEJyNrxhfUY9eBoPgQcKuCnoMePFmBPOAZAmzk95kzDyWmVkhLPkHLx4U8er/ePNvnCR70MSChqKqm+6uKOHMWN//9gorq2vrG8XN0tb2zu5eef+gaVSqKTSo4kq3I2KAMwkNyyyHdqKBiIhDKxrdTP3WE2jDlHyw4wRCQQaSxYwS66Rm907AgPTKFb/qz4CXSZCTCspR75W/un1FUwHSUk6M6QR+YsOMaMsoh0mpmxpICB2RAXQclUSACbPZtRN84pQ+jpV2JS2eqb8nMiKMGYvIdQpih2bRm4r/eZ3UxtdhxmSSWpB0vihOObYKT1/HfaaBWj52hFDN3K2YDokm1LqASi6EYPHlZdI8rwYX1eD+slI7y+MooiN0jE5RgK5QDd2iOmogih7RM3pFb57yXrx372PeWvDymUP0B97nD1mPjug=</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringScattering cross section
The wave function at a spatial position r = sum of transmitted and scattered spherical wave function.
vscatk (r) = eikr + fk(✓,')eikr
r<latexit sha1_base64="AJOQ7wuRf/Fi9beL7BqaG/Wr7vU=">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</latexit>
Only depends on the scattering
potential .
fk(✓,')<latexit sha1_base64="BIZkHoNkvOfq+Grffrs01iITa3o=">AAAB/HicbVBNS8NAEN3Ur1q/oj16CRahQimJCnosePFYwX5AE8Jmu2mWbjZhd1IIpf4VLx4U8eoP8ea/cdvmoK0PBh7vzTAzL0g5U2Db30ZpY3Nre6e8W9nbPzg8Mo9PuirJJKEdkvBE9gOsKGeCdoABp/1UUhwHnPaC8d3c702oVCwRj5Cn1IvxSLCQEQxa8s1q6I/rLkQUcMOdYJlG7MI3a3bTXsBaJ05BaqhA2ze/3GFCspgKIBwrNXDsFLwplsAIp7OKmymaYjLGIzrQVOCYKm+6OH5mnWtlaIWJ1CXAWqi/J6Y4ViqPA90ZY4jUqjcX//MGGYS33pSJNAMqyHJRmHELEmuehDVkkhLguSaYSKZvtUiEJSag86roEJzVl9dJ97LpXDWdh+taq1HEUUan6AzVkYNuUAvdozbqIIJy9Ixe0ZvxZLwY78bHsrVkFDNV9AfG5w8f/ZRb</latexit>
V (r)<latexit sha1_base64="2oFztpCCnfp5VoK6zrEuOWGXBYc=">AAAB9HicbVDLSgMxFL1TX7W+qi7dBItQQcqMCrosuHFZwT6gHUomzbShmWRMMoUy9DvcuFDErR/jzr8x085CWw8EDufcyz05QcyZNq777RTW1jc2t4rbpZ3dvf2D8uFRS8tEEdokkkvVCbCmnAnaNMxw2okVxVHAaTsY32V+e0KVZlI8mmlM/QgPBQsZwcZKfqvai7AZBWGqZuf9csWtuXOgVeLlpAI5Gv3yV28gSRJRYQjHWnc9NzZ+ipVhhNNZqZdoGmMyxkPatVTgiGo/nYeeoTOrDFAolX3CoLn6eyPFkdbTKLCTWUS97GXif143MeGtnzIRJ4YKsjgUJhwZibIG0IApSgyfWoKJYjYrIiOsMDG2p5ItwVv+8ippXda8q5r3cF2pX+R1FOEETqEKHtxAHe6hAU0g8ATP8ApvzsR5cd6dj8Vowcl3juEPnM8fZJORyA==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringScattering cross section
‣ mediated by strong force, short ranged (fm = 10-15 m)
‣ neutron wavelength much larger (10-10 m) cannot probe internal structure scattering is isotropic
‣ the interaction between the neutron and the atomic nucleus is
represented by the Fermi pseudo-potential, a scalar field that is 0
except very close to the nucleus V (r) =2⇡~2mn
b�3(r)<latexit sha1_base64="71yGz+YYUKXXmQawjH+4Un/QqZU=">AAACJXicbVDLSgMxFM34rPU16tJNsAgVpMy0gi4UCm5cVrAP6LQlk2ba0CQzJBmhDPMzbvwVNy4sIrjyV8y0XdTWA4HDOeeSe48fMaq043xba+sbm1vbuZ387t7+waF9dNxQYSwxqeOQhbLlI0UYFaSuqWakFUmCuM9I0x/dZ37zmUhFQ/GkxxHpcDQQNKAYaSP17NtG0eNID/0gkekFvINeIBFOyl5EvaGPZLecJrwnUt/rE6ZRt7IY79kFp+RMAVeJOycFMEetZ0+8fohjToTGDCnVdp1IdxIkNcWMpHkvViRCeIQGpG2oQJyoTjK9MoXnRunDIJTmCQ2n6uJEgrhSY+6bZLaiWvYy8T+vHevgppNQEcWaCDz7KIgZ1CHMKoN9KgnWbGwIwpKaXSEeIlOTNsXmTQnu8smrpFEuuZWS+3hVqF7O68iBU3AGisAF16AKHkAN1AEGL+ANfICJ9Wq9W5/W1yy6Zs1nTsAfWD+/jy2lQA==</latexit>
advantage: neutron senses atomic position and not the electron cloud (bonds)
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringScattering cross section
The scattering amplitude is related to the Fourier transform of the potential function.
With the Fermi pseudo potential for neutron scattering from a nucleus
Neutron scattering from a nucleus is isotropic!
b is in the order of 10-12 cm
fk(✓,') = � 1
4⇡
2µ
~2
ZV (r)e�ikrd3r
<latexit sha1_base64="6K5Lg3ALed7S5pVoGgyuvm7y8tM=">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</latexit>
V (r) =2⇡~2mn
b�3(r)<latexit sha1_base64="71yGz+YYUKXXmQawjH+4Un/QqZU=">AAACJXicbVDLSgMxFM34rPU16tJNsAgVpMy0gi4UCm5cVrAP6LQlk2ba0CQzJBmhDPMzbvwVNy4sIrjyV8y0XdTWA4HDOeeSe48fMaq043xba+sbm1vbuZ387t7+waF9dNxQYSwxqeOQhbLlI0UYFaSuqWakFUmCuM9I0x/dZ37zmUhFQ/GkxxHpcDQQNKAYaSP17NtG0eNID/0gkekFvINeIBFOyl5EvaGPZLecJrwnUt/rE6ZRt7IY79kFp+RMAVeJOycFMEetZ0+8fohjToTGDCnVdp1IdxIkNcWMpHkvViRCeIQGpG2oQJyoTjK9MoXnRunDIJTmCQ2n6uJEgrhSY+6bZLaiWvYy8T+vHevgppNQEcWaCDz7KIgZ1CHMKoN9KgnWbGwIwpKaXSEeIlOTNsXmTQnu8smrpFEuuZWS+3hVqF7O68iBU3AGisAF16AKHkAN1AEGL+ANfICJ9Wq9W5/W1yy6Zs1nTsAfWD+/jy2lQA==</latexit>
|fk(✓,')| = b<latexit sha1_base64="1sWirUCD0ePZJv0N//7D21ddJTM=">AAACAHicbVBNS8NAEN34WetX1IMHL8EiVCglUUEvQsGLxwr2A5oQNttNu3SzCbuTQkl78a948aCIV3+GN/+N2zYHbX0w8Hhvhpl5QcKZAtv+NlZW19Y3Ngtbxe2d3b198+CwqeJUEtogMY9lO8CKciZoAxhw2k4kxVHAaSsY3E391pBKxWLxCKOEehHuCRYygkFLvnk8Dv1B2YU+BVxxh1gmfXY+vg18s2RX7RmsZeLkpIRy1H3zy+3GJI2oAMKxUh3HTsDLsARGOJ0U3VTRBJMB7tGOpgJHVHnZ7IGJdaaVrhXGUpcAa6b+nshwpNQoCnRnhKGvFr2p+J/XSSG88TImkhSoIPNFYcotiK1pGlaXSUqAjzTBRDJ9q0X6WGICOrOiDsFZfHmZNC+qzmXVebgq1Sp5HAV0gk5RGTnoGtXQPaqjBiJogp7RK3oznowX4934mLeuGPnMEfoD4/MHPpqWGg==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringComparison to X-rays
The amplitude of the scattered wave (the Fourier transform of the potential function) is called the atomic form factor f (X-rays) or scattering length b (neutrons).
Nucleus ~10-15 m
Electron shell ~10-10 m
advantage with neutrons: scattered intensity does not drop with increasing scattering angle
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringComparison to X-rays
Scattering lengths (analog to X-ray form factor)
superposition of resonance scattering with slowly increasing potential scattering due to atomic weight
advantages:
contrast between neighbouring elements light elements can be measured easily
isotope effect (bH=-3.7, bD=6.8)
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Nuclear scatteringComparison to X-rays
Scattering lengths (analog to X-ray form factor)
superposition of resonance scattering with slowly increasing potential scattering due to atomic weight
advantages:
contrast between neighbouring elements light elements can be measured easily
isotope effect (bH=-3.7, bD=6.8)
K+
Cl-Example KCl:
scattering lengths of K and Cl are very different strong contrast
X-rays would see a primitive cell with half the lattice constant
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringElectron magnetic moment
Magnetic dipole moment in classical electrodynamics
µ = I ·A<latexit sha1_base64="SGDC0ONJB3FjiX4lIuLs+FurSZI=">AAAB+HicbVDLSsNAFJ34rPXRqEs3g0VwISVRQTdCxY3uKtgHNKFMJpN26DzCzESooV/ixoUibv0Ud/6N0zYLbT1w4XDOvdx7T5Qyqo3nfTtLyyura+uljfLm1vZOxd3da2mZKUyaWDKpOhHShFFBmoYaRjqpIohHjLSj4c3Ebz8SpakUD2aUkpCjvqAJxchYqedWAp7BK3gHAxxLA697btWreVPAReIXpAoKNHruVxBLnHEiDGZI667vpSbMkTIUMzIuB5kmKcJD1CddSwXiRIf59PAxPLJKDBOpbAkDp+rviRxxrUc8sp0cmYGe9ybif143M8llmFORZoYIPFuUZAwaCScpwJgqgg0bWYKwovZWiAdIIWxsVmUbgj//8iJpndb8s5p/f16tnxRxlMABOATHwAcXoA5uQQM0AQYZeAav4M15cl6cd+dj1rrkFDP74A+czx+q4JG5</latexit>
=�e · ve2⇡r
· ⇡r2 =�e · ve
2· r =
�e
2m·mver = � e
2mL
<latexit sha1_base64="f/FdZivhpEIm4Ivndxw5kZ+OIFA=">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</latexit>
Gyromagnetic ratio : ratio between magnetic dipole moment and total angular momentum�<latexit sha1_base64="rb2AirB/XSr2+pnI4GtwbIWRgLA=">AAAB7XicbVDLSgNBEOz1GeMr6tHLYBA8SNhVQY8BLx4jmAckS+idzCZjZnaWmVkhhPyDFw+KePV/vPk3TpI9aGJBQ1HVTXdXlApurO9/eyura+sbm4Wt4vbO7t5+6eCwYVSmKatTJZRuRWiY4AmrW24Fa6WaoYwEa0bD26nffGLacJU82FHKQon9hMeconVSo9NHKbFbKvsVfwayTIKclCFHrVv66vQUzSRLLBVoTDvwUxuOUVtOBZsUO5lhKdIh9lnb0QQlM+F4du2EnDqlR2KlXSWWzNTfE2OUxoxk5Dol2oFZ9Kbif147s/FNOOZJmlmW0PmiOBPEKjJ9nfS4ZtSKkSNINXe3EjpAjdS6gIouhGDx5WXSuKgEl5Xg/qpcPc/jKMAxnMAZBHANVbiDGtSBwiM8wyu8ecp78d69j3nripfPHMEfeJ8/gUmPAg==</latexit>
� = � e
2m= �µB
~<latexit sha1_base64="UVYUikRPVQWHJWCEKHn6zKnrdSg=">AAACFHicbVDLSgMxFM3UV62vqks3wSIIapmpgm4KRTcuK9gHdEq5k2ba0GRmSDJCGeYj3Pgrblwo4taFO//GtJ2Fth64cHLOveTe40WcKW3b31ZuaXlldS2/XtjY3NreKe7uNVUYS0IbJOShbHugKGcBbWimOW1HkoLwOG15o5uJ33qgUrEwuNfjiHYFDALmMwLaSL3iiTsAIQBX8ZnrSyAJTZOKSKvZyxVx7zpN3KEHMu0VS3bZngIvEicjJZSh3it+uf2QxIIGmnBQquPYke4mIDUjnKYFN1Y0AjKCAe0YGoCgqptMj0rxkVH62A+lqUDjqfp7IgGh1Fh4plOAHqp5byL+53Vi7V91ExZEsaYBmX3kxxzrEE8Swn0mKdF8bAgQycyumAzBpKFNjgUTgjN/8iJpVsrOedm5uyjVTrM48ugAHaJj5KBLVEO3qI4aiKBH9Ixe0Zv1ZL1Y79bHrDVnZTP76A+szx9uN55l</latexit>
µB =e~2me
<latexit sha1_base64="DaiN8n8rPRlKINZGrfy3MSD+tbI=">AAACAnicbVBNS8NAEN3Ur1q/op7ES7AIHqQkVdCLUPTisYL9gCaEzXbSLt1Nwu5GKCF48a948aCIV3+FN/+N2zYHbX0w8Hhvhpl5QcKoVLb9bZSWlldW18rrlY3Nre0dc3evLeNUEGiRmMWiG2AJjEbQUlQx6CYCMA8YdILRzcTvPICQNI7u1TgBj+NBRENKsNKSbx64PPWvr9xQYJKBOwywyLM69yH3zapds6ewFolTkCoq0PTNL7cfk5RDpAjDUvYcO1FehoWihEFecVMJCSYjPICephHmIL1s+kJuHWulb4Wx0BUpa6r+nsgwl3LMA93JsRrKeW8i/uf1UhVeehmNklRBRGaLwpRZKrYmeVh9KoAoNtYEE0H1rRYZYp2G0qlVdAjO/MuLpF2vOWc15+682jgt4iijQ3SETpCDLlAD3aImaiGCHtEzekVvxpPxYrwbH7PWklHM7KM/MD5/AF1jl1c=</latexit>
with
This works well for the electron’s orbital momentum, but its intrinsic spin momentum cannot be explained in the classical approach correction by g-factor
� = �geµB
~<latexit sha1_base64="6KC019gZtpyC9z3zqRNFAL1rZ/o=">AAACCXicbVDLSsNAFJ34rPUVdelmsAgutCQq6EYounFZwT6gCeFmOkmHziRhZiKU0K0bf8WNC0Xc+gfu/Bunj4W2HrhwOOde7r0nzDhT2nG+rYXFpeWV1dJaeX1jc2vb3tltqjSXhDZIylPZDkFRzhLa0Exz2s4kBRFy2gr7NyO/9UClYmlyrwcZ9QXECYsYAW2kwMZeDEIAvsIncUC9SAIpPJEH18PC64Ugh4FdcarOGHieuFNSQVPUA/vL66YkFzTRhINSHdfJtF+A1IxwOix7uaIZkD7EtGNoAoIqvxh/MsSHRuniKJWmEo3H6u+JAoRSAxGaTgG6p2a9kfif18l1dOkXLMlyTRMyWRTlHOsUj2LBXSYp0XxgCBDJzK2Y9MCkoU14ZROCO/vyPGmeVt2zqnt3XqkdT+MooX10gI6Qiy5QDd2iOmoggh7RM3pFb9aT9WK9Wx+T1gVrOrOH/sD6/AHuD5nM</latexit>
(gL = 1, gS = 2)
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringElectron magnetic moment
Angular momenta are quantised in units of
spin moment (1 per electron spin)
orbital moment (1 per )
Total moment due to LS coupling :
The magnetic moment of en electron is quantised in
Spin momenta are quantised in units of 1/2
~<latexit sha1_base64="10Uu+MJGiNZ5co/h0xjPZwIDYH0=">AAAB7HicbVBNS8NAEJ3Ur1q/qh69LBbBg5REBT0WvHisYNpCG8pku2mXbjZhdyOU0N/gxYMiXv1B3vw3btsctPXBwOO9GWbmhang2rjut1NaW9/Y3CpvV3Z29/YPqodHLZ1kijKfJiJRnRA1E1wy33AjWCdVDONQsHY4vpv57SemNE/ko5mkLIhxKHnEKRor+b1RiKpfrbl1dw6ySryC1KBAs1/96g0SmsVMGipQ667npibIURlOBZtWeplmKdIxDlnXUokx00E+P3ZKzqwyIFGibElD5urviRxjrSdxaDtjNCO97M3E/7xuZqLbIOcyzQyTdLEoygQxCZl9TgZcMWrExBKkittbCR2hQmpsPhUbgrf88ippXda9q7r3cF1rXBRxlOEETuEcPLiBBtxDE3ygwOEZXuHNkc6L8+58LFpLTjFzDH/gfP4Av7GOkg==</latexit>
(L = ...,�2~,�~, 0, ~, 2~, ...)<latexit sha1_base64="5PXW7D7bVDXrj5iKTT8OQYVg5iU=">AAACGnicbZDLSgMxFIbP1Futt1GXboJFqFCHmSroRii4ceGigr1AO5RMmmlDMxeSjFCGPocbX8WNC0XciRvfxrQdQVsPhHz8/zkk5/dizqSy7S8jt7S8srqWXy9sbG5t75i7ew0ZJYLQOol4JFoelpSzkNYVU5y2YkFx4HHa9IZXE795T4VkUXinRjF1A9wPmc8IVlrqmk7pBl0iy7LK6KTSGXhYaMhuu4wy+nF033HXLNqWPS20CE4GRciq1jU/Or2IJAENFeFYyrZjx8pNsVCMcDoudBJJY0yGuE/bGkMcUOmm09XG6EgrPeRHQp9Qoan6eyLFgZSjwNOdAVYDOe9NxP+8dqL8CzdlYZwoGpLZQ37CkYrQJCfUY4ISxUcaMBFM/xWRARaYKJ1mQYfgzK+8CI2K5Zxazu1ZsVrO4sjDARxCCRw4hypcQw3qQOABnuAFXo1H49l4M95nrTkjm9mHP2V8fgMiqptK</latexit>
� = �geµB
~<latexit sha1_base64="6KC019gZtpyC9z3zqRNFAL1rZ/o=">AAACCXicbVDLSsNAFJ34rPUVdelmsAgutCQq6EYounFZwT6gCeFmOkmHziRhZiKU0K0bf8WNC0Xc+gfu/Bunj4W2HrhwOOde7r0nzDhT2nG+rYXFpeWV1dJaeX1jc2vb3tltqjSXhDZIylPZDkFRzhLa0Exz2s4kBRFy2gr7NyO/9UClYmlyrwcZ9QXECYsYAW2kwMZeDEIAvsIncUC9SAIpPJEH18PC64Ugh4FdcarOGHieuFNSQVPUA/vL66YkFzTRhINSHdfJtF+A1IxwOix7uaIZkD7EtGNoAoIqvxh/MsSHRuniKJWmEo3H6u+JAoRSAxGaTgG6p2a9kfif18l1dOkXLMlyTRMyWRTlHOsUj2LBXSYp0XxgCBDJzK2Y9MCkoU14ZROCO/vyPGmeVt2zqnt3XqkdT+MooX10gI6Qiy5QDd2iOmoggh7RM3pFb9aT9WK9Wx+T1gVrOrOH/sD6/AHuD5nM</latexit>
(gL = 1, gS = 2)
µB<latexit sha1_base64="C91P0K5ZAOqTt0uUUTQMZ8yaSh8=">AAAB7HicbVDLSgNBEOyNrxhfUY9eBoPgQcKuCnoMevEYwTWBZAmzk9lkyMzsMg8hLPkGLx4U8eoHefNvnCR70MSChqKqm+6uOONMG9//9korq2vrG+XNytb2zu5edf/gUadWERqSlKeqHWNNOZM0NMxw2s4UxSLmtBWPbqd+64kqzVL5YMYZjQQeSJYwgo2Twq6wvZtetebX/RnQMgkKUoMCzV71q9tPiRVUGsKx1p3Az0yUY2UY4XRS6VpNM0xGeEA7jkosqI7y2bETdOKUPkpS5UoaNFN/T+RYaD0WsesU2Az1ojcV//M61iTXUc5kZg2VZL4osRyZFE0/R32mKDF87AgmirlbERlihYlx+VRcCMHiy8vk8bweXNSD+8ta46yIowxHcAynEMAVNOAOmhACAQbP8ApvnvRevHfvY95a8oqZQ/gD7/MHmHyOeA==</latexit>
µB<latexit sha1_base64="C91P0K5ZAOqTt0uUUTQMZ8yaSh8=">AAAB7HicbVDLSgNBEOyNrxhfUY9eBoPgQcKuCnoMevEYwTWBZAmzk9lkyMzsMg8hLPkGLx4U8eoHefNvnCR70MSChqKqm+6uOONMG9//9korq2vrG+XNytb2zu5edf/gUadWERqSlKeqHWNNOZM0NMxw2s4UxSLmtBWPbqd+64kqzVL5YMYZjQQeSJYwgo2Twq6wvZtetebX/RnQMgkKUoMCzV71q9tPiRVUGsKx1p3Az0yUY2UY4XRS6VpNM0xGeEA7jkosqI7y2bETdOKUPkpS5UoaNFN/T+RYaD0WsesU2Az1ojcV//M61iTXUc5kZg2VZL4osRyZFE0/R32mKDF87AgmirlbERlihYlx+VRcCMHiy8vk8bweXNSD+8ta46yIowxHcAynEMAVNOAOmhACAQbP8ApvnvRevHfvY95a8oqZQ/gD7/MHmHyOeA==</latexit> ~
<latexit sha1_base64="10Uu+MJGiNZ5co/h0xjPZwIDYH0=">AAAB7HicbVBNS8NAEJ3Ur1q/qh69LBbBg5REBT0WvHisYNpCG8pku2mXbjZhdyOU0N/gxYMiXv1B3vw3btsctPXBwOO9GWbmhang2rjut1NaW9/Y3CpvV3Z29/YPqodHLZ1kijKfJiJRnRA1E1wy33AjWCdVDONQsHY4vpv57SemNE/ko5mkLIhxKHnEKRor+b1RiKpfrbl1dw6ySryC1KBAs1/96g0SmsVMGipQ667npibIURlOBZtWeplmKdIxDlnXUokx00E+P3ZKzqwyIFGibElD5urviRxjrSdxaDtjNCO97M3E/7xuZqLbIOcyzQyTdLEoygQxCZl9TgZcMWrExBKkittbCR2hQmpsPhUbgrf88ippXda9q7r3cF1rXBRxlOEETuEcPLiBBtxDE3ygwOEZXuHNkc6L8+58LFpLTjFzDH/gfP4Av7GOkg==</latexit>
~<latexit sha1_base64="10Uu+MJGiNZ5co/h0xjPZwIDYH0=">AAAB7HicbVBNS8NAEJ3Ur1q/qh69LBbBg5REBT0WvHisYNpCG8pku2mXbjZhdyOU0N/gxYMiXv1B3vw3btsctPXBwOO9GWbmhang2rjut1NaW9/Y3CpvV3Z29/YPqodHLZ1kijKfJiJRnRA1E1wy33AjWCdVDONQsHY4vpv57SemNE/ko5mkLIhxKHnEKRor+b1RiKpfrbl1dw6ySryC1KBAs1/96g0SmsVMGipQ667npibIURlOBZtWeplmKdIxDlnXUokx00E+P3ZKzqwyIFGibElD5urviRxjrSdxaDtjNCO97M3E/7xuZqLbIOcyzQyTdLEoygQxCZl9TgZcMWrExBKkittbCR2hQmpsPhUbgrf88ippXda9q7r3cF1rXBRxlOEETuEcPLiBBtxDE3ygwOEZXuHNkc6L8+58LFpLTjFzDH/gfP4Av7GOkg==</latexit>
(S = ...� 3
2~,�~,�1
2~, 0, 1
2~, ~, 3
2~, ...)
<latexit sha1_base64="a/TUfE0kbskrDuVaBLkm10ZdMLM=">AAACUXicbVHLSgMxFL0zvmrro+rSTbAIFdphphV0IxTcuKxoH9CWkkkzbWjmQZIRytBfdKEr/8ONC8W0HaW2Xgj3cM59JCduxJlUtv1mmBubW9s7md1sbm//4DB/dNyUYSwIbZCQh6LtYkk5C2hDMcVpOxIU+y6nLXd8O9NbT1RIFgaPahLRno+HAfMYwUpT/fyo+IBukGVZ5a4nMEmq06Qy7Y5cLEqo/JvnkrMk2SW0Tv6ktUF6/EU/X7Atex5oHTgpKEAa9X7+pTsISezTQBGOpew4dqR6CRaKEU6n2W4saYTJGA9pR8MA+1T2krkjU3SumQHyQqFPoNCcXe5IsC/lxHd1pY/VSK5qM/I/rRMr77qXsCCKFQ3IYpEXc6RCNLMXDZigRPGJBpgIpu+KyAhrQ5T+hKw2wVl98jpoViynajn3l4VaKbUjA6dwBkVw4ApqcAd1aACBZ3iHT/gyXo0PE0xzUWoaac8J/Akz9w2+Xq+x</latexit>
µB<latexit sha1_base64="C91P0K5ZAOqTt0uUUTQMZ8yaSh8=">AAAB7HicbVDLSgNBEOyNrxhfUY9eBoPgQcKuCnoMevEYwTWBZAmzk9lkyMzsMg8hLPkGLx4U8eoHefNvnCR70MSChqKqm+6uOONMG9//9korq2vrG+XNytb2zu5edf/gUadWERqSlKeqHWNNOZM0NMxw2s4UxSLmtBWPbqd+64kqzVL5YMYZjQQeSJYwgo2Twq6wvZtetebX/RnQMgkKUoMCzV71q9tPiRVUGsKx1p3Az0yUY2UY4XRS6VpNM0xGeEA7jkosqI7y2bETdOKUPkpS5UoaNFN/T+RYaD0WsesU2Az1ojcV//M61iTXUc5kZg2VZL4osRyZFE0/R32mKDF87AgmirlbERlihYlx+VRcCMHiy8vk8bweXNSD+8ta46yIowxHcAynEMAVNOAOmhACAQbP8ApvnvRevHfvY95a8oqZQ/gD7/MHmHyOeA==</latexit>
J = L+ S<latexit sha1_base64="d0MZjqYK3RK52/KNigjYVtvbkWg=">AAACCXicbZDLSsNAFIZPvNZ6i7p0M1gEQSmJCroRCm5EXFS0F2hDmUwn7dDJhZmJUEK2bnwVNy4UcesbuPNtnLQpaOsPAx//OYc553cjzqSyrG9jbn5hcWm5sFJcXVvf2DS3tusyjAWhNRLyUDRdLClnAa0ppjhtRoJi3+W04Q4us3rjgQrJwuBeDSPq+LgXMI8RrLTVMVHbx6rvesl1ejHBm/RwgndpxyxZZWskNAt2DiXIVe2YX+1uSGKfBopwLGXLtiLlJFgoRjhNi+1Y0giTAe7RlsYA+1Q6yeiSFO1rp4u8UOgXKDRyf08k2Jdy6Lu6M9tQTtcy879aK1beuZOwIIoVDcj4Iy/mSIUoiwV1maBE8aEGTATTuyLSxwITpcMr6hDs6ZNnoX5ctk/K9u1pqXKUx1GAXdiDA7DhDCpwBVWoAYFHeIZXeDOejBfj3fgYt84Z+cwO/JHx+QMLK5p7</latexit>
µJ = �gJµBJ
~<latexit sha1_base64="T5isWqwvQyVy70/aju/IEKB43qc=">AAACHnicbVDLSsNAFJ3UV62vqEs3g0VwoSXxgW6EohvpqoJ9QBPCZDJph04mYWYilJAvceOvuHGhiOBK/8ZJ24W2HhjmcM693HuPnzAqlWV9G6WFxaXllfJqZW19Y3PL3N5pyzgVmLRwzGLR9ZEkjHLSUlQx0k0EQZHPSMcf3hR+54EISWN+r0YJcSPU5zSkGCkteea548cskKNIf5kTpbnXgFfHfa+huXfthAJhLSM18MOskeeZM/CRyD2zatWsMeA8saekCqZoeuanE8Q4jQhXmCEpe7aVKDdDQlHMSF5xUkkShIeoT3qachQR6Wbj83J4oJUAhrHQjys4Vn93ZCiSxQW6sthUznqF+J/XS1V46WaUJ6kiHE8GhSmDKoZFVjCggmDFRpogLKjeFeIB0pEonWhFh2DPnjxP2ic1+7Rm351V60fTOMpgD+yDQ2CDC1AHt6AJWgCDR/AMXsGb8WS8GO/Gx6S0ZEx7dsEfGF8/5tijhg==</latexit>
µS = �S = � e
meS = �2µB
S
~<latexit sha1_base64="hSyDTpJEO8ONYe87U5xa/VM5qK4=">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</latexit>
µL = �L = � e
2meL = �µB
L
~<latexit sha1_base64="jWhlM63hbvd5AhmtRfSuQhV3KrM=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringNeutron magnetic moment
Gyromagnetic ratios of common spin-1/2 particles:
Neutron moment is around 960 times smaller than the electron moment.
Nuclear magnetons:
proton neutron
For neutrons: with
Protons, neutrons and many nuclei carry a nuclear spin.1.76·105 MHz/T 267 MHz/T
183 MHz/T
Electron: Proton:
Neutron:
µN =e~2mp
<latexit sha1_base64="15SQVA/2WvX0mgNyGGlSyfMy5XY=">AAACAnicbVDLSsNAFJ3UV62vqCtxM1gEF1KSKuhGKLhxJRXsA5oQJtNJO3RmEmYmQgnBjb/ixoUibv0Kd/6N0zYLbT1w4XDOvdx7T5gwqrTjfFulpeWV1bXyemVjc2t7x97da6s4lZi0cMxi2Q2RIowK0tJUM9JNJEE8ZKQTjq4nfueBSEVjca/HCfE5GggaUYy0kQL7wONpcHvlRRLhjHjDEMk8q/MgyQO76tScKeAicQtSBQWagf3l9WOcciI0Zkipnusk2s+Q1BQzkle8VJEE4REakJ6hAnGi/Gz6Qg6PjdKHUSxNCQ2n6u+JDHGlxjw0nRzpoZr3JuJ/Xi/V0aWfUZGkmgg8WxSlDOoYTvKAfSoJ1mxsCMKSmlshHiKThjapVUwI7vzLi6Rdr7lnNffuvNo4LeIog0NwBE6ACy5AA9yAJmgBDB7BM3gFb9aT9WK9Wx+z1pJVzOyDP7A+fwCBOpdu</latexit>
µp = 2.793µN<latexit sha1_base64="HsB2JBc63+FI1W/FmC9sIthJCUc=">AAACAnicbVDLSsNAFJ34rPUVdSVugkVwISFphepCKLhxJRXsA5oQJtNJO3QmGWYmQgnFjb/ixoUibv0Kd/6NkzYLbT1w4XDOvdx7T8gpkcpxvo2l5ZXVtfXSRnlza3tn19zbb8skFQi3UEIT0Q2hxJTEuKWIorjLBYYspLgTjq5zv/OAhSRJfK/GHPsMDmISEQSVlgLz0GNpwK+qdv2y5jE5IrzG0ly7DcyKYztTWIvELUgFFGgG5pfXT1DKcKwQhVL2XIcrP4NCEUTxpOylEnOIRnCAe5rGkGHpZ9MXJtaJVvpWlAhdsbKm6u+JDDIpxyzUnQyqoZz3cvE/r5eq6MLPSMxThWM0WxSl1FKJledh9YnASNGxJhAJom+10BAKiJROraxDcOdfXiTtqu3WbPfuvNI4K+IogSNwDE6BC+qgAW5AE7QAAo/gGbyCN+PJeDHejY9Z65JRzByAPzA+fwDY35Zf</latexit>
µn = �µN�<latexit sha1_base64="LDx5HBq1eNMugLTVOvp0NsaxHzk=">AAACGnicbVDLSgMxFM34rPU16tLNYBFcSJlRQTdCwY0rqWAf0CnDnUymDU0yQ5IRytDvcOOvuHGhiDtx49+YabuwrQdCTs65l9x7wpRRpV33x1paXlldWy9tlDe3tnd27b39pkoyiUkDJyyR7RAUYVSQhqaakXYqCfCQkVY4uCn81iORiibiQQ9T0uXQEzSmGLSRAtvzw4RFasjNlfs8GwXi2u8B52Aewd2Mq2iPwyiwK27VHcNZJN6UVNAU9cD+8qMEZ5wIjRko1fHcVHdzkJpiRkZlP1MkBTyAHukYKoAT1c3Hq42cY6NETpxIc4R2xurfjhy4KuYzlRx0X817hfif18l0fNXNqUgzTQSefBRnzNGJU+TkRFQSrNnQEMCSmlkd3AcJWJs0yyYEb37lRdI8q3rnVe/+olI7ncZRQofoCJ0gD12iGrpFddRAGD2hF/SG3q1n69X6sD4npUvWtOcAzcD6/gXsF6KX</latexit>
�n = �1.913<latexit sha1_base64="MUTUqTy7WF+eg9jwkg0YpPa672c=">AAAB+HicbVDLSgMxFM3UV62Pjrp0EyyCCy0TK6gLoeDGZQX7gHYYMmmmDU0yQ5IR6tAvceNCEbd+ijv/xrSdhbYeuHA4517uvSdMONPG876dwsrq2vpGcbO0tb2zW3b39ls6ThWhTRLzWHVCrClnkjYNM5x2EkWxCDlth6Pbqd9+pEqzWD6YcUJ9gQeSRYxgY6XALfcGWAgcyJszVL1GtcCteFVvBrhMUE4qIEcjcL96/ZikgkpDONa6i7zE+BlWhhFOJ6VeqmmCyQgPaNdSiQXVfjY7fAKPrdKHUaxsSQNn6u+JDAutxyK0nQKboV70puJ/Xjc10ZWfMZmkhkoyXxSlHJoYTlOAfaYoMXxsCSaK2VshGWKFibFZlWwIaPHlZdI6r6JaFd1fVOqneRxFcAiOwAlA4BLUwR1ogCYgIAXP4BW8OU/Oi/PufMxbC04+cwD+wPn8AbrMkcA=</latexit>
µn = �1.913µN<latexit sha1_base64="3uDnR9vpIZzzKtpYWo2YoHdtg2M=">AAACA3icbVDLSsNAFJ3UV62vqDvdBIvgQkNiBXUhFNy4kgr2AU0Ik+mkHTozCTMToYSCG3/FjQtF3PoT7vwbJ20W2nrgwuGce7n3njChRCrH+TZKC4tLyyvl1cra+sbmlrm905JxKhBuopjGohNCiSnhuKmIoriTCAxZSHE7HF7nfvsBC0lifq9GCfYZ7HMSEQSVlgJzz2NpwK9OXPvSrXlMDklSY2ku3gZm1bGdCax54hakCgo0AvPL68UoZZgrRKGUXddJlJ9BoQiieFzxUokTiIawj7uacsiw9LPJD2PrUCs9K4qFLq6sifp7IoNMyhELdSeDaiBnvVz8z+umKrrwM8KTVGGOpouilFoqtvJArB4RGCk60gQiQfStFhpAAZHSsVV0CO7sy/OkdWq7Ndu9O6vWj4s4ymAfHIAj4IJzUAc3oAGaAIFH8AxewZvxZLwY78bHtLVkFDO74A+Mzx85vpaN</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringMagnetic scattering potential
Magnetic scattering: interaction of the neutron spin with the magnetic field of an unpaired electron
gyromagnetic ratio
nuclear magneton
The interaction is described by the potential:
neutron spin operator:
Magnetic scattering length proportional to electron radius e2/mec2:
comparable to nuclear scattering
Pauli spin operator
µ = �µN �<latexit sha1_base64="odeUAMhLGCSWci+h7MHyLLhhnkg=">AAACJHicbVDLSsNAFJ34rPVVdekmWAQXUhIVFEQouHElFewDmhBuJpN06EwSZiZCCfkYN/6KGxc+cOHGb3HaZqGtF4Y5nHMu997jp4xKZVlfxsLi0vLKamWtur6xubVd29ntyCQTmLRxwhLR80ESRmPSVlQx0ksFAe4z0vWH12O9+0CEpEl8r0YpcTlEMQ0pBqUpr3bp+AkL5IjrL3cGoHKHZ0Vx5UTAOWjs3c47JI04FIVXq1sNa1LmPLBLUEdltbzauxMkOOMkVpiBlH3bSpWbg1AUM1JUnUySFPAQItLXMAZOpJtPjizMQ80EZpgI/WJlTtjfHTlwOd5SOzmogZzVxuR/Wj9T4YWb0zjNFInxdFCYMVMl5jgxM6CCYMVGGgAWVO9q4gEIwErnWtUh2LMnz4POScM+bdh3Z/XmcRlHBe2jA3SEbHSOmugGtVAbYfSIntErejOejBfjw/icWheMsmcP/Snj+wfTyKdQ</latexit>
�µ ·H = ��µN � ·H<latexit sha1_base64="8sH/GMNN25E35b5tadzJltq/RZ0=">AAACRHicbVBNSwMxFMz6bf2qevSyWAQPWnZV0ItQ8OJJKlgVuqW8zWbbYLJZkrdCWfbHefEHePMXePGgiFcx2/ag1gchw8wbMpkwFdyg5z07U9Mzs3PzC4uVpeWV1bXq+sa1UZmmrEWVUPo2BMMET1gLOQp2m2oGMhTsJrw7K/Wbe6YNV8kVDlLWkdBLeMwpoKW61fZ+ECoRmYG0Vx70AfNAZkUR0EhhIAH7YZyfF6f7QQ+kBKt1LyYdhvckTJi61ZpX94bjTgJ/DGpkPM1u9SmIFM0kS5AKMKbteyl2ctDIqWBFJcgMS4HeQY+1LUxAMtPJhyUU7o5lIjdW2p4E3SH705GDNGVou1kmNH+1kvxPa2cYn3RynqQZsoSOHooz4aJyy0bdiGtGUQwsAKq5zerSPmigaHuv2BL8v1+eBNcHdf+w7l8e1Rp74zoWyBbZJrvEJ8ekQc5Jk7QIJQ/khbyRd+fReXU+nM/R6pQz9mySX+N8fQMwUrUS</latexit>
�r0 =�e2
mec2= �0.54 · 10�12 cm
<latexit sha1_base64="TYX1+KQ3HDTg2+ZNU98YIjmqABE=">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</latexit>
� = �1.91<latexit sha1_base64="vRhmV35C4V9APslV9l37lvGzVQg=">AAAB9XicbVBNSwMxEM36WetX1aOXYBE86LKrgnoQCl48VrAf0K5lNs22oUl2SbJKWfo/vHhQxKv/xZv/xrTdg7Y+GHi8N8PMvDDhTBvP+3YWFpeWV1YLa8X1jc2t7dLObl3HqSK0RmIeq2YImnImac0ww2kzURREyGkjHNyM/cYjVZrF8t4MExoI6EkWMQLGSg/tHggB+Bqf+O6V3ymVPdebAM8TPydllKPaKX21uzFJBZWGcNC65XuJCTJQhhFOR8V2qmkCZAA92rJUgqA6yCZXj/ChVbo4ipUtafBE/T2RgdB6KELbKcD09aw3Fv/zWqmJLoOMySQ1VJLpoijl2MR4HAHuMkWJ4UNLgChmb8WkDwqIsUEVbQj+7MvzpH7q+meuf3derhzncRTQPjpAR8hHF6iCblEV1RBBCj2jV/TmPDkvzrvzMW1dcPKZPfQHzucP8yyQxQ==</latexit>
µN =meµB
mn<latexit sha1_base64="CxbcxdXUGqpccFqyZ/Mlfv2dzkQ=">AAACBXicbZDLSsNAFIYn9VbrLepSF4NFcCElUUE3QtGNK6lgL9CUMJlO2qEzkzAzEUrIxo2v4saFIm59B3e+jZM2C239YeDjP+dw5vxBzKjSjvNtlRYWl5ZXyquVtfWNzS17e6elokRi0sQRi2QnQIowKkhTU81IJ5YE8YCRdjC6zuvtByIVjcS9Hsekx9FA0JBipI3l2/seT/xbeAm9UCKccp/kxlVmSGS+XXVqzkRwHtwCqqBQw7e/vH6EE06Exgwp1XWdWPdSJDXFjGQVL1EkRniEBqRrUCBOVC+dXJHBQ+P0YRhJ84SGE/f3RIq4UmMemE6O9FDN1nLzv1o30eFFL6UiTjQReLooTBjUEcwjgX0qCdZsbABhSc1fIR4iE4c2wVVMCO7syfPQOqm5pzX37qxaPy7iKIM9cACOgAvOQR3cgAZoAgwewTN4BW/Wk/VivVsf09aSVczsgj+yPn8AJFGYSg==</latexit>
�<latexit sha1_base64="5vyVUvDdfe+SAN0ZueANJQBgd24=">AAACAnicbVDLSsNAFJ3UV62vqCtxM1gEF1ISFXRZcOOygq2FJpTJZNIOnUeYmQglFDf+ihsXirj1K9z5N07aLLT1wDCHc+7l3nuilFFtPO/bqSwtr6yuVddrG5tb2zvu7l5Hy0xh0saSSdWNkCaMCtI21DDSTRVBPGLkPhpdF/79A1GaSnFnxikJORoImlCMjJX67kEQSRbrMbdfHgyRyQNNBxxNJn237jW8KeAi8UtSByVaffcriCXOOBEGM6R1z/dSE+ZIGYoZmdSCTJMU4REakJ6lAnGiw3x6wgQeWyWGiVT2CQOn6u+OHHFdbGkrOTJDPe8V4n9eLzPJVZhTkWaGCDwblGQMGgmLPGBMFcGGjS1BWFG7K8RDpBA2NrWaDcGfP3mRdM4a/nnDv72oN0/LOKrgEByBE+CDS9AEN6AF2gCDR/AMXsGb8+S8OO/Ox6y04pQ9++APnM8fkJGYGw==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
@2�
@⌦@E= r20
kfki
X
↵�
⇣�↵� � k↵k�
⌘
| {z }sum over directions xyz
X
��0
p�h�|k2↵|�0ih�|k2
� |�0i�(~! + E� � E�0)
| {z }sum and average over final �0 and initial states �
<latexit sha1_base64="B5aduig8edCxBtPR9tAfjzhP/ck=">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</latexit>
Magnetic scatteringMagnetic scattering potential
Magnetic field due to a single electron moving with velocity ve:
(from S. W. Lovesey, Theory of Neutron Scattering from
Condensed Matter, Volume 2)H = curl
✓µe ⇥R
|R|3
◆
| {z }spin motion
+�e
c
ve ⇥R
|R|3| {z }orbital motion
<latexit sha1_base64="KEIG9mtWvL9+W2qdGEWwjERPFzc=">AAADD3icjZJNb9QwEIad8FWWj27hyMViVakIWCUUiV6QKnHpsSC2rbReVo4z2bXqfMieVF25/gdc+CtcOIAQV67c+Dc42ZTSFiFGivL6nbHn8chJpaTBKPoZhFeuXrt+Y+Vm79btO3dX+2v39kxZawEjUapSHyTcgJIFjFCigoNKA88TBfvJ4asmv38E2siyeIuLCiY5nxUyk4Kjt6ZrwTrLOc6TzO44+pKy9kSrIXWsLlLQieYCbGcniotDxxCO0YpaK8cUZLjBMl9kWVKq1Cxy/7Msr90UGMocDD1t8MY5e3K2OHm36ZiWszk+ctP2TJ1bU8mC5mXD5ui5ro//B40uUZ6Cs8J1WF3Do99A/+A5Ayl1IpGrU5ZpfxANozboZRF3YkC62J32f7C0FHUOBQrFjRnHUYUTyzVKocD1WG2g8sh8BmMvC+7BJra9i6Pr3klpVmr/FUhb988dluemmbSvbPDNxVxj/i03rjHbmlhZVDVCIZaNslpRLGnzOGgqNQhUCy+40NKzUjHnfozon1DPDyG+eOXLYu/ZMN4cxq+fD7afdONYIQ/IQ7JBYvKCbJMdsktGRATvg4/B5+BL+CH8FH4Nvy1Lw6Dbc5+ci/D7L6g/Bdc=</latexit>
The scattering cross section between the neutron and the electron becomes (after 2 pages):
In comparison to nuclear scattering the magnetic cross section has a directional dependence!
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringMagnetic scattering potential
Like for nuclear scattering the Born approximation holds and the scattered amplitude is the Fourier transformation of the potential function (atomic magnetisation density), the magnetic form factor.
which is defined by:
g, gL, gS: g-factors jn: spherical Bessel functions
f(k) =
Z⇢(r) exp(ikr)dr
<latexit sha1_base64="HcCdNITRYsWwP09l1Ao8rrgXqJA=">AAACMXicbVDLSsNAFJ3UV62vqEs3wSK0ICVRQTdCwU2XFewDmlAmk0k7dDIJMxOxhPySG/9E3HShiFt/wkkbbG09MHA451zm3uNGlAhpmhOtsLa+sblV3C7t7O7tH+iHR20RxhzhFgppyLsuFJgShluSSIq7EccwcCnuuKO7zO88Yi5IyB7kOMJOAAeM+ARBqaS+3vArdgDl0PWTUVq9tQmTNh+GvyJPqzZ+iipknlqwvDnv62WzZk5hrBIrJ2WQo9nXX20vRHGAmUQUCtGzzEg6CeSSIIrTkh0LHEE0ggPcU5TBAAsnmV6cGmdK8Qw/5OoxaUzVxYkEBkKMA1clsw3FspeJ/3m9WPo3TkJYFEvM0OwjP6aGDI2sPsMjHCNJx4pAxIna1UBDyCGSquSSKsFaPnmVtC9q1mXNur8q18/zOorgBJyCCrDANaiDBmiCFkDgGbyBd/ChvWgT7VP7mkULWj5zDP5A+/4B2KWryg==</latexit>
f(k) =gSgj0(k) +
gLg
[j0(k) + j2(k)]<latexit sha1_base64="S9nYiMafoa9Jq5u6VWqToDZ5rvw=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic scatteringMagnetic scattering potential
Like for nuclear scattering the Born approximation holds and the scattered amplitude is the Fourier transformation of the potential function (atomic magnetisation density), the magnetic form factor.
which is defined by:
g, gL, gS: g-factors jn: spherical Bessel functions
f(k) =
Z⇢(r) exp(ikr)dr
<latexit sha1_base64="HcCdNITRYsWwP09l1Ao8rrgXqJA=">AAACMXicbVDLSsNAFJ3UV62vqEs3wSK0ICVRQTdCwU2XFewDmlAmk0k7dDIJMxOxhPySG/9E3HShiFt/wkkbbG09MHA451zm3uNGlAhpmhOtsLa+sblV3C7t7O7tH+iHR20RxhzhFgppyLsuFJgShluSSIq7EccwcCnuuKO7zO88Yi5IyB7kOMJOAAeM+ARBqaS+3vArdgDl0PWTUVq9tQmTNh+GvyJPqzZ+iipknlqwvDnv62WzZk5hrBIrJ2WQo9nXX20vRHGAmUQUCtGzzEg6CeSSIIrTkh0LHEE0ggPcU5TBAAsnmV6cGmdK8Qw/5OoxaUzVxYkEBkKMA1clsw3FspeJ/3m9WPo3TkJYFEvM0OwjP6aGDI2sPsMjHCNJx4pAxIna1UBDyCGSquSSKsFaPnmVtC9q1mXNur8q18/zOorgBJyCCrDANaiDBmiCFkDgGbyBd/ChvWgT7VP7mkULWj5zDP5A+/4B2KWryg==</latexit>
f(k) =gSgj0(k) +
gLg
[j0(k) + j2(k)]<latexit sha1_base64="S9nYiMafoa9Jq5u6VWqToDZ5rvw=">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</latexit>
analytical approximation:
coefficients a, A, b, B, c, C, D tabulated on http://www.ill.eu/sites/ccsl/html/ccsldoc.html)
j0(s) = A exp(�as2) +B exp(�bs2) + C exp(�cs2) +D<latexit sha1_base64="vvPEXSl3wR4vTHVsvZw4dcKRhTQ=">AAACGHicbVDLSgMxFM3UV62vUZdugkVoUetMFXQjVOvCZQX7gHYsmTTTxmYeJBmxDP0MN/6KGxeKuO3OvzGdmYVaLwTO415u7rEDRoU0jC8tMze/sLiUXc6trK6tb+ibWw3hhxyTOvaZz1s2EoRRj9QllYy0Ak6QazPStIfVqd98IFxQ37uVo4BYLup71KEYSSV19aP7rlEQxfOLDnkMCodI3JWL+5cJsWNSTQiOyVVXzxslIy44C8wU5EFata4+6fR8HLrEk5ghIdqmEUgrQlxSzMg41wkFCRAeoj5pK+ghlwgrig8bwz2l9KDjc/U8CWP150SEXCFGrq06XSQH4q83Ff/z2qF0zqyIekEoiYeTRU7IoPThNCXYo5xgyUYKIMyp+ivEA8QRlirLnArB/HvyLGiUS+Zxybw5yVcO0jiyYAfsggIwwSmogGtQA3WAwRN4AW/gXXvWXrUP7TNpzWjpzDb4VdrkGxI/nJc=</latexit>
j2(s) =⇥A exp(�as2) +B exp(�bs2) + C exp(�cs2) +D
⇤· s2
<latexit sha1_base64="bwM+jzPS0TqEiwZ5NAi9Z50FTVE=">AAACLnicbVDJSgNBEO1xN25Rj14agxBRw0wU9CLEDTwqGBUyY+jp1CStPQvdNWII+SIv/ooeBBXx6mfYmeTgVtDwliqq6/mJFBpt+8UaGh4ZHRufmMxNTc/MzuXnF851nCoOVR7LWF36TIMUEVRRoITLRAELfQkX/s1Bz7+4BaVFHJ1hOwEvZM1IBIIzNFI9f3RdLxf16q4rIcDangt3SXGD6avy6tp+n/gZOegTnpFDV4lmCz2XN2KkRqrnC3bJzor+Bc4AFMigTur5J7cR8zSECLlkWtccO0GvwxQKLqGbc1MNCeM3rAk1AyMWgvY62bldumKUBg1iZV6ENFO/T3RYqHU79E1nyLClf3s98T+vlmKw43VElKQIEe8vClJJMaa97GhDKOAo2wYwroT5K+UtphhHk3DOhOD8PvkvOC+XnM2Sc7pVqKwP4pggS2SZFIlDtkmFHJMTUiWc3JNH8krerAfr2Xq3PvqtQ9ZgZpH8KOvzC6yrpdc=</latexit>
s =sin ✓
�<latexit sha1_base64="btOr0DE5g16Xp5fa5lZD5ADLI9k=">AAACBXicbVDLSsNAFJ3UV62vqEtdDBbBhZREBd0IBTcuK9gHNKFMppN26GQSZm6EErJx46+4caGIW//BnX/jtM1CWw9cOJxz78y9J0gE1+A431ZpaXllda28XtnY3NresXf3WjpOFWVNGotYdQKimeCSNYGDYJ1EMRIFgrWD0c3Ebz8wpXks72GcMD8iA8lDTgkYqWcf6msvVIRmnubSgyEDkmeeMA/0Sd6zq07NmQIvErcgVVSg0bO/vH5M04hJoIJo3XWdBPyMKOBUsLzipZolhI7IgHUNlSRi2s+mV+T42Ch9HMbKlAQ8VX9PZCTSehwFpjMiMNTz3kT8z+umEF75GZdJCkzS2UdhKjDEeBIJ7nPFKIixIYQqbnbFdEhMKGCCq5gQ3PmTF0nrrOae19y7i2r9tIijjA7QETpBLrpEdXSLGqiJKHpEz+gVvVlP1ov1bn3MWktWMbOP/sD6/AF075kd</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresOrdered magnetic state
In some crystals, some of the atoms/ions have unpaired electrons (transition metals, rare-earths).
Hund’s rule favors a state with maximum S and L. The ions possess a localised magnetic moment.
Exchange interactions (direct, superexchange, double exchange, RKKY, dipolar, …) often stabilize a long-range magnetic order
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
The magnetic structure does not necessarily have the same periodicity and symmetry as the underlying crystal structure. The relation between one and another is expressed by the propagation or wave vector.
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
The magnetic structure does not necessarily have the same periodicity and symmetry as the underlying crystal structure. The relation between one and another is expressed by the propagation or wave vector.
ferromagnetic
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
The magnetic structure does not necessarily have the same periodicity and symmetry as the underlying crystal structure. The relation between one and another is expressed by the propagation or wave vector.
antiferromagnetic
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
The magnetic structure does not necessarily have the same periodicity and symmetry as the underlying crystal structure. The relation between one and another is expressed by the propagation or wave vector.
commensurate antiferromagnetic
magnetic periodicity = 2 x nuclear periodicity ! q = (1/2 0 0)<latexit sha1_base64="CjWYkiBz1GYa55ETkeLFpVWDU1s=">AAACC3icbVDLSgMxFM3UV62vUZduQotQQepMFXQjFNy4rGAf0BlKJs20oZlkTDJKGbp346+4caGIW3/AnX9jpu1CWw8JHM65l3vvCWJGlXacbyu3tLyyupZfL2xsbm3v2Lt7TSUSiUkDCyZkO0CKMMpJQ1PNSDuWBEUBI61geJX5rXsiFRX8Vo9i4keoz2lIMdJG6tpFT9L+QCMpxQP0IqQHQZjejS/L7knVg455R1275FScCeAicWekBGaod+0vrydwEhGuMUNKdVwn1n6KpKaYkXHBSxSJER6iPukYylFElJ9ObhnDQ6P0YCik+VzDifq7I0WRUqMoMJXZtmrey8T/vE6iwws/pTxONOF4OihMGNQCZsHAHpUEazYyBGFJza4QD5BEWJv4CiYEd/7kRdKsVtzTintzVqodz+LIgwNQBGXggnNQA9egDhoAg0fwDF7Bm/VkvVjv1se0NGfNevbBH1ifP54XmWA=</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
The magnetic structure does not necessarily have the same periodicity and symmetry as the underlying crystal structure. The relation between one and another is expressed by the propagation or wave vector.
commensurate antiferromagnetic
magnetic periodicity = x times nuclear periodicity ! q = (1/x 0 0)<latexit sha1_base64="Pg+Y9AQbVwCKb6RBs89sBW/TGf4=">AAACC3icbVDLSgMxFM3UV62vUZduQotQQeqMCroRCm5cVrAP6Awlk2ba0EwyJhm1DN278VfcuFDErT/gzr8x03ahrYcEDufcy733BDGjSjvOt5VbWFxaXsmvFtbWNza37O2dhhKJxKSOBROyFSBFGOWkrqlmpBVLgqKAkWYwuMz85h2Rigp+o4cx8SPU4zSkGGkjdeyiJ2mvr5GU4h56EdL9IExvRxdl9+jBg455Bx275FScMeA8caekBKaodewvrytwEhGuMUNKtV0n1n6KpKaYkVHBSxSJER6gHmkbylFElJ+ObxnBfaN0YSik+VzDsfq7I0WRUsMoMJXZtmrWy8T/vHaiw3M/pTxONOF4MihMGNQCZsHALpUEazY0BGFJza4Q95FEWJv4CiYEd/bkedI4rrgnFff6tFQ9nMaRB3ugCMrABWegCq5ADdQBBo/gGbyCN+vJerHerY9Jac6a9uyCP7A+fwAKKJmm</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresPropagation vector
Magnetic Bragg reflections can be found at
commensurate AF incommensurate AFferromagnetic
Magnetic satellites for
k = G± q<latexit sha1_base64="pvnua7XFfnAuwies5n4jD3WM3tI=">AAACDHicbVDLSsNAFL3xWeur6tLNYBFcSElU0I1QcKHLCvYBbSiT6aQdOpnEmYlQQj7Ajb/ixoUibv0Ad/6NkzYFbT0wcOace7n3Hi/iTGnb/rYWFpeWV1YLa8X1jc2t7dLObkOFsSS0TkIeypaHFeVM0LpmmtNWJCkOPE6b3vAq85sPVCoWijs9iqgb4L5gPiNYG6lbKncCrAeenwzTyym9TjtRgKa/+9RU2RV7DDRPnJyUIUetW/rq9EISB1RowrFSbceOtJtgqRnhNC12YkUjTIa4T9uGChxQ5SbjY1J0aJQe8kNpntBorP7uSHCg1CjwTGW2oZr1MvE/rx1r/8JNmIhiTQWZDPJjjnSIsmRQj0lKNB8ZgolkZldEBlhiok1+RROCM3vyPGmcVJzTinN7Vq4e53EUYB8O4AgcOIcq3EAN6kDgEZ7hFd6sJ+vFerc+JqULVt6zB39gff4AxymcAQ==</latexit>
superposition for q 6= 0<latexit sha1_base64="ctWQp9cWVaWsCrbK90LXzaTPxU0=">AAAB+XicdVDLSgMxFM3UV62vUZdugkVwIUOmL7ssuHFZwT6gM5RMmmlDM5lpkimUoX/ixoUibv0Td/6N6UNQ0QOBwzn3ck9OkHCmNEIfVm5jc2t7J79b2Ns/ODyyj0/aKk4loS0S81h2A6woZ4K2NNOcdhNJcRRw2gnGNwu/M6VSsVjc61lC/QgPBQsZwdpIfdv2IqxHQZhN5p6gE4j6dhE5qFau1V2InGoVVSslQ+o1t1SpQddBSxTBGs2+/e4NYpJGVGjCsVI9FyXaz7DUjHA6L3ipogkmYzykPUMFjqjys2XyObwwygCGsTRPaLhUv29kOFJqFgVmcpFT/fYW4l9eL9Vh3c+YSFJNBVkdClMOdQwXNcABk5RoPjMEE8lMVkhGWGKiTVkFU8LXT+H/pF1y3LLj3lWKjat1HXlwBs7BJXDBNWiAW9AELUDAFDyAJ/BsZdaj9WK9rkZz1nrnFPyA9fYJudSTpw==</latexit>
q = 0<latexit sha1_base64="ZbdWQAwUuN2Y9LBwDkOwpAWfBX4=">AAAB9HicdVDLSgMxFM3UV62vqks3wSK4kCHTx9iNUHDjsoJthXYomTTThmYy0yRTKEO/w40LRdz6Me78GzNtBRU9EDiccy/35PgxZ0oj9GHl1tY3Nrfy24Wd3b39g+LhUVtFiSS0RSIeyXsfK8qZoC3NNKf3saQ49Dnt+OPrzO9MqVQsEnd6FlMvxEPBAkawNpLXC7Ee+UE6mV9B1C+WkI3cilt3ILJrNVSrlg2pu0656kLHRguUwArNfvG9N4hIElKhCcdKdR0Uay/FUjPC6bzQSxSNMRnjIe0aKnBIlZcuQs/hmVEGMIikeULDhfp9I8WhUrPQN5NZSPXby8S/vG6ig7qXMhEnmgqyPBQkHOoIZg3AAZOUaD4zBBPJTFZIRlhiok1PBVPC10/h/6Rdtp2K7dxWS42LVR15cAJOwTlwwCVogBvQBC1AwAQ8gCfwbE2tR+vFel2O5qzVzjH4AevtE6cNkfU=</latexit>
q = (1/2 0 0)<latexit sha1_base64="kPMUl7NwZVW4ra+Q9XD9j/2gGoc=">AAACAnicbVDLSsNAFL3xWesr6krcDBahgtSkCroRCm5cVrAPaEKZTCft0MnDmYlQQnHjr7hxoYhbv8Kdf+OkzUJbD1w4nHMv997jxZxJZVnfxsLi0vLKamGtuL6xubVt7uw2ZZQIQhsk4pFoe1hSzkLaUExx2o4FxYHHacsbXmd+64EKyaLwTo1i6ga4HzKfEay01DX3nQCrgeen92N0hcr2adVBFtJ13DVLVsWaAM0TOyclyFHvml9OLyJJQENFOJayY1uxclMsFCOcjotOImmMyRD3aUfTEAdUuunkhTE60koP+ZHQFSo0UX9PpDiQchR4ujM7WM56mfif10mUf+mmLIwTRUMyXeQnHKkIZXmgHhOUKD7SBBPB9K2IDLDAROnUijoEe/bledKsVuyzin17Xqqd5HEU4AAOoQw2XEANbqAODSDwCM/wCm/Gk/FivBsf09YFI5/Zgz8wPn8AM5aUoQ==</latexit>
q = (1/2� � 0 0)<latexit sha1_base64="nPkzv7RLbegnX8nB4Z8bY1vHUKM=">AAACCXicbVDLSsNAFJ34rPUVdelmsAgVtCZV0I1QcOOygn1AE8pkOmmHTh7O3AgldOvGX3HjQhG3/oE7/8ZJm4W2HrhwOOde7r3HiwVXYFnfxsLi0vLKamGtuL6xubVt7uw2VZRIyho0EpFse0QxwUPWAA6CtWPJSOAJ1vKG15nfemBS8Si8g1HM3ID0Q+5zSkBLXRM7AYGB56f3Y3yFy/Zp9cTpMQHEwRbWddQ1S1bFmgDPEzsnJZSj3jW/nF5Ek4CFQAVRqmNbMbgpkcCpYOOikygWEzokfdbRNCQBU246+WSMD7XSw34kdYWAJ+rviZQESo0CT3dmd6tZLxP/8zoJ+JduysM4ARbS6SI/ERginMWCe1wyCmKkCaGS61sxHRBJKOjwijoEe/bledKsVuyzin17Xqod53EU0D46QGVkowtUQzeojhqIokf0jF7Rm/FkvBjvxse0dcHIZ/bQHxifP2C7l3o=</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresFourier expansion of magnetic moments
One usually describes magnetic structures with Fourier components of the magnetic moments:
which for a single propagation vector becomes:
Since is a real vector, one must impose the condition
is a complex vector made of linear combinations of basis vectors according to one or more
µ(r)<latexit sha1_base64="hyypYzjrmxI1o/Z14x8V8Td6ns8=">AAACBXicbVDLSsNAFJ34rPUVdamLwSJUkJKooMuCG5cV7AOaUCaTSTt0MhNmJkIJ2bjxV9y4UMSt/+DOv3HSZqGtF4Y5nHMv99wTJIwq7Tjf1tLyyuraemWjurm1vbNr7+13lEglJm0smJC9ACnCKCdtTTUjvUQSFAeMdIPxTaF3H4hUVPB7PUmIH6MhpxHFSBtqYB95gWChmsTmy7w4zetejPQoiDKZnw7smtNwpgUXgVuCGiirNbC/vFDgNCZcY4aU6rtOov0MSU0xI3nVSxVJEB6jIekbyFFMlJ9Nr8jhiWFCGAlpHtdwyv6eyFCsCqOms7Co5rWC/E/rpzq69jPKk1QTjmeLopRBLWARCQypJFiziQEIS2q8QjxCEmFtgquaENz5kxdB57zhXjTcu8ta86yMowIOwTGoAxdcgSa4BS3QBhg8gmfwCt6sJ+vFerc+Zq1LVjlzAP6U9fkDT32ZAg==</latexit>
S⇤�q = Sq
<latexit sha1_base64="GDKPmuvVwRCMhUG7gM+bjk+wVoo=">AAACB3icbVDLSsNAFJ3UV62vqEtBBosgoiVRQTdCwY3LivYBbQyT6aQOnUzSmYlQQnZu/BU3LhRx6y+482+ctAG19cCFwzn3cu89XsSoVJb1ZRRmZufmF4qLpaXlldU1c32jIcNYYFLHIQtFy0OSMMpJXVHFSCsSBAUeI02vf5H5zXsiJA35jRpGxAlQj1OfYqS05JrbnQCpO89PrtPbfTc5HKTnP4o7cM2yVbFGgNPEzkkZ5Ki55menG+I4IFxhhqRs21aknAQJRTEjaakTSxIh3Ec90taUo4BIJxn9kcJdrXShHwpdXMGR+nsiQYGUw8DTndmNctLLxP+8dqz8MyehPIoV4Xi8yI8ZVCHMQoFdKghWbKgJwoLqWyG+QwJhpaMr6RDsyZenSeOoYh9X7KuTcvUgj6MItsAO2AM2OAVVcAlqoA4weABP4AW8Go/Gs/FmvI9bC0Y+swn+wPj4BkgamYA=</latexit>
µ(r) =1
nq
X
q
Sq · e�iqr
<latexit sha1_base64="4C8bPOu0snR1ThJ7U93PNfZ/7RI=">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</latexit>
Sq<latexit sha1_base64="lcVPafchoFH4IrWqxpftTObQKxo=">AAAB83icbVDLSgMxFL1TX7W+qi7dBIvgQsqMCrosuHFZ0T6gM5RMmmlDM8mYZIQy9DfcuFDErT/jzr8x085CWw8EDufcyz05YcKZNq777ZRWVtfWN8qbla3tnd296v5BW8tUEdoikkvVDbGmnAnaMsxw2k0UxXHIaScc3+R+54kqzaR4MJOEBjEeChYxgo2VfD/GZhRG2f20/9iv1ty6OwNaJl5BalCg2a9++QNJ0pgKQzjWuue5iQkyrAwjnE4rfqppgskYD2nPUoFjqoNslnmKTqwyQJFU9gmDZurvjQzHWk/i0E7mGfWil4v/eb3URNdBxkSSGirI/FCUcmQkygtAA6YoMXxiCSaK2ayIjLDCxNiaKrYEb/HLy6R9Xvcu6t7dZa1xVtRRhiM4hlPw4AoacAtNaAGBBJ7hFd6c1Hlx3p2P+WjJKXYO4Q+czx9NO5HI</latexit>
irreducible representations.
µ(r) =1
2(Sq · e�iqr + S�q · eiqr)
<latexit sha1_base64="01nTBKMzUbKvrc9ydGxhA9xZYIY=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresTypes of magnetic structures
real Fourier components
q=0 ferromagnetic q=(100) antiferromagnetic (centered cells)
µ(r) = Sq · e�iqr = Sq<latexit sha1_base64="vhdquXe1DU14IaYM8WpKdPf1JYw=">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</latexit>
µ(r) =1
2(Sq · e�iqr + S�q · eiqr) = Sq · (�1)2rx
<latexit sha1_base64="ou9Mw+sZOoOV3vtAB6F+jfcmESE=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresTypes of magnetic structures
real Fourier components
antiferromagnetic, q=1/2G (at the border of the 1st Brillouin zone)
µ(r) =1
2(Sq · e�iqr + S�q · eiqr) = Sq · (�1)rx
<latexit sha1_base64="baGyCf3fdOLwWsvIJceTA8laHHs=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresTypes of magnetic structures
imaginary Fourier components (real and imaginary parts parallel)
amplitude-modulated antiferromagnetic, q<1/2G (at the interior of the 1st Brillouin zone)
Sq = µue�iqr<latexit sha1_base64="+4FRHT+i9VOMZ+xw5CGsg94cj9g=">AAACJXicbZDLSsNAFIYnXmu9RV26GSyCCy2JCrpQKLhxWdFeoIlhMp20QyeTdGYilJCXceOruHFhEcGVr+KkF9DWHwZ+vnMOc87vx4xKZVlfxsLi0vLKamGtuL6xubVt7uzWZZQITGo4YpFo+kgSRjmpKaoYacaCoNBnpOH3bvJ644kISSP+oAYxcUPU4TSgGCmNPPPKCZHq+kF6n3l9eA2dMJkSp4tUmmQZeUxP6BT2s6kTWeaZJatsjQTnjT0xJTBR1TOHTjvCSUi4wgxJ2bKtWLkpEopiRrKik0gSI9xDHdLSlqOQSDcdXZnBQ03aMIiEflzBEf09kaJQykHo6858RTlby+F/tVaigks3pTxOFOF4/FGQMKgimEcG21QQrNhAG4QF1btC3EUCYaWDLeoQ7NmT5039tGyfle2781LleBJHAeyDA3AEbHABKuAWVEENYPAMXsE7GBovxpvxYXyOWxeMycwe+CPj+weWPKcg</latexit>
µ(r) = µu cos [2⇡(qr+ �q)]<latexit sha1_base64="szqg1NF4p2lmhuwiW8wDGSNpdiU=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresTypes of magnetic structures
antiferromagnetic spirals, q<1/2G (at the interior of the 1st Brillouin zone)
helicoidal cycloidal
Sq = (µuu+ iµvv) e�iqr
<latexit sha1_base64="LwdK2kI6OdgZDu5i/wM0nPVoH5s=">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</latexit>
imaginary Fourier components (real and imaginary parts perpendicular)
µ(r) = µuu cos [2⇡(qr+ �q)] + µvv sin [2⇡(qr+ �q)]<latexit sha1_base64="fqiPfvGzaOUfwRckCqs9Bsx4Vzk=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Magnetic structuresTypes of magnetic structures
multi-q structures, e.g. conical (ferromagnetic q=0 component + helix)
treatment of every component separately
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Scattering from a unit cellReminder: Nuclear structure factor
imagine two scattering potentials (atoms), the first at 0, the second at r
The path difference is:
Therefore, the phase difference is:
Sum up phase differences over atoms in unit cell:
Structure factor F(hkl) is the Fourier transform of the unit cell scattering potential.
�s(r) = r · kf
kf� r · ki
ki<latexit sha1_base64="uV1Yp1ay4xPRibOMA4kdTImxFIw=">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</latexit>
'(r) = 2⇡�s
�= k ·�s = (kf � ki) · r = G · r
<latexit sha1_base64="7yMEA+O3gwsRBdNi2lVQcnW4KTY=">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</latexit>
F (hkl) =X
j
bj exp(iGrj) =X
j
bj exp [2⇡i(hxj + kyj + lzj)]
<latexit sha1_base64="e2znaFfHzEkXMOaXsGUbjlmjb08=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Scattering from a unit cellMagnetic structure factor
The magnetic structure factor is obtained in the same way, but it is also proportional to the magnetic moment of the involved atoms directional dependence, FM is a vector
Only the component of FM which is perpendicular to k contributes to magnetic scattering:
Equivalent: Projection of FM onto (hkl) plane
kFM
QM(hkl)
QM = k⇥ (FM ⇥ k)<latexit sha1_base64="7ei+NYty4fx2ZXyaTzI3k82k5TI=">AAACMHicbVDLSsNAFJ34rPUVdekmWIQKUhIVdCMUBHUjtGAf0IQymU7aoZMHMzdCCfkkN36KbhQUcetXOGlT0NYDA2fOPZd773EjziSY5pu2sLi0vLJaWCuub2xubes7u00ZxoLQBgl5KNoulpSzgDaAAaftSFDsu5y23OFVVm89UCFZGNzDKKKOj/sB8xjBoKSufmP7GAaul9TT7t3l9GMPMCTDNLWB+VSWp/K18kykWeNRVy+ZFXMMY55YOSmhHLWu/mz3QhL7NADCsZQdy4zASbAARjhNi3YsaYTJEPdpR9EAq6lOMj44NQ6V0jO8UKgXgDFWf3ck2Jdy5LvKmS0qZ2uZ+F+tE4N34SQsiGKgAZkM8mJuQGhk6Rk9JigBPlIEE8HUrgYZYIEJqIyLKgRr9uR50jypWKcVq35Wqh7ncRTQPjpAZWShc1RFt6iGGoigR/SC3tGH9qS9ap/a18S6oOU9e+gPtO8f982r5w==</latexit>
FM (hkl) =X
j
µjfj(k) exp(ikrj) =X
j
µjfj(k) exp [2⇡i(hxj + kyj + lzj)]
<latexit sha1_base64="CKsEhjzVRx+7vzzv8kiaw628xBE=">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</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Scattering from a unit cellExample: Ferromagnetic structure
FM (hkl) =X
j
µjfj(k) exp(ikrj) =X
j
µjfj(k) exp [2⇡i(hxj + kyj + lzj)]
<latexit sha1_base64="CKsEhjzVRx+7vzzv8kiaw628xBE=">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</latexit>
FM (100) =
0
@0µ0
1
A f(k)
<latexit sha1_base64="gbAvliniSC0uRMmR4GFpbcVUZtI=">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</latexit>
QM (100) = FM (100)<latexit sha1_base64="ABf09uSQGBkfS3B6615CZdvA9HU=">AAACDHicbVDLSgMxFL1TX7W+qi7dBItQQcqMCroRCoK4EVqwD2hLyaSZNjSTGZKMUIZ+gBt/xY0LRdz6Ae78GzPtFLT1QOBwzrnk3uOGnClt299WZml5ZXUtu57b2Nza3snv7tVVEElCayTggWy6WFHOBK1ppjlthpJi3+W04Q6vE7/xQKVigbjXo5B2fNwXzGMEayN184W2j/XA9eLquHtXdGz7+Gqm3MwUk7JL9gRokTgpKUCKSjf/1e4FJPKp0IRjpVqOHepOjKVmhNNxrh0pGmIyxH3aMlRgn6pOPDlmjI6M0kNeIM0TGk3U3xMx9pUa+a5JJouqeS8R//NakfYuOzETYaSpINOPvIgjHaCkGdRjkhLNR4ZgIpnZFZEBlpho01/OlODMn7xI6qcl56zkVM8L5ZO0jiwcwCEUwYELKMMtVKAGBB7hGV7hzXqyXqx362MazVjpzD78gfX5A8pwmXI=</latexit>
FM (010) =
0
@0µ0
1
A f(k)
<latexit sha1_base64="LIlnkeBSfn6KvO4jSkSOucRHe7k=">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</latexit>
FM (110) =
0
@0µ0
1
A f(k)
<latexit sha1_base64="AT93HZD0DexfuOc+ZNcLeNGVPqE=">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</latexit>
FM (001) =
0
@0µ0
1
A f(k)
<latexit sha1_base64="VUBjjBzQR/tPm31+/27fJ8oTsqI=">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</latexit>
QM (001) = FM (001)<latexit sha1_base64="BPuslFPZeedngHSZpuUpkirr33I=">AAACDHicbVDLSgMxFL1TX7W+qi7dBItQQcqMCroRCoK4EVqwD2hLyaSZNjSTGZKMUIZ+gBt/xY0LRdz6Ae78GzPtFLT1QOBwzrnk3uOGnClt299WZml5ZXUtu57b2Nza3snv7tVVEElCayTggWy6WFHOBK1ppjlthpJi3+W04Q6vE7/xQKVigbjXo5B2fNwXzGMEayN184W2j/XA9eLquHtXtG3n+Gqm3MwUk7JL9gRokTgpKUCKSjf/1e4FJPKp0IRjpVqOHepOjKVmhNNxrh0pGmIyxH3aMlRgn6pOPDlmjI6M0kNeIM0TGk3U3xMx9pUa+a5JJouqeS8R//NakfYuOzETYaSpINOPvIgjHaCkGdRjkhLNR4ZgIpnZFZEBlpho01/OlODMn7xI6qcl56zkVM8L5ZO0jiwcwCEUwYELKMMtVKAGBB7hGV7hzXqyXqx362MazVjpzD78gfX5A8psmXI=</latexit>
QM (110) = FM (110) sin↵<latexit sha1_base64="IgdC9gI+ANb+uqaaDfkuAwb6wt8=">AAACFnicbZDLSsNAFIYn9VbrLerSzWARKmhJVNCNUBDEjdCCvUATwmQ6aYdOJmFmIpTQp3Djq7hxoYhbcefbOGlT0OoPAz/fOYc55/djRqWyrC+jsLC4tLxSXC2trW9sbpnbOy0ZJQKTJo5YJDo+koRRTpqKKkY6sSAo9Blp+8OrrN6+J0LSiN+pUUzcEPU5DShGSiPPPHZCpAZ+kDbG3m3Ftq3Dyxm5nhFHUu4gFg+QZ5atqjUR/Gvs3JRBrrpnfjq9CCch4QozJGXXtmLlpkgoihkZl5xEkhjhIeqTrrYchUS66eSsMTzQpAeDSOjHFZzQnxMpCqUchb7uzFaW87UM/lfrJiq4cFPK40QRjqcfBQmDKoJZRrBHBcGKjbRBWFC9K8QDJBBWOsmSDsGeP/mvaZ1U7dOq3Tgr147yOIpgD+yDCrDBOaiBG1AHTYDBA3gCL+DVeDSejTfjfdpaMPKZXfBLxsc35FWd4A==</latexit>
QM (010) = 0<latexit sha1_base64="Kde6otUWfl3agh0YPpw+dJ/SnyU=">AAAB/HicbVDLSgMxFM34rPU12qWbYBEqSMmooBuh4MaN0IJ9QDsMmTTThmYyQ5IRhqH+ihsXirj1Q9z5N2baWWjrgcDhnHu5J8ePOVMaoW9rZXVtfWOztFXe3tnd27cPDjsqSiShbRLxSPZ8rChngrY105z2Yklx6HPa9Se3ud99pFKxSDzoNKZuiEeCBYxgbSTPrgxCrMd+kLWm3n0NOej0Bnl2FdXRDHCZOAWpggJNz/4aDCOShFRowrFSfQfF2s2w1IxwOi0PEkVjTCZ4RPuGChxS5Waz8FN4YpQhDCJpntBwpv7eyHCoVBr6ZjKPqha9XPzP6yc6uHYzJuJEU0Hmh4KEQx3BvAk4ZJISzVNDMJHMZIVkjCUm2vRVNiU4i19eJp3zunNRd1qX1cZZUUcJHIFjUAMOuAINcAeaoA0ISMEzeAVv1pP1Yr1bH/PRFavYqYA/sD5/AK/Pk2g=</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
collimator defines the beam shape and divergence
Soller collimators, slits
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
monochromator (assembly of) high quality single crystals
choice of wavelength and resolution typically Cu, Ge, HOPG, Si
diffracts also higher harmonics 𝜆/2, 𝜆/3, …n� = 2d sin ✓
<latexit sha1_base64="v5uBK8oDE0UJjEW9awQ8/p1DiJw=">AAACAHicbVDLSsNAFJ3UV62vqAsXbgaL4EJKUgXdCAU3LivYBzShTCaTduhkEmZuhBK68VfcuFDErZ/hzr9x2mahrQcGDuecy517glRwDY7zbZVWVtfWN8qbla3tnd09e/+grZNMUdaiiUhUNyCaCS5ZCzgI1k0VI3EgWCcY3U79ziNTmifyAcYp82MykDzilICR+vaR9IRJhwTf4HroaS49GDIgfbvq1JwZ8DJxC1JFBZp9+8sLE5rFTAIVROue66Tg50QBp4JNKl6mWUroiAxYz1BJYqb9fHbABJ8aJcRRosyTgGfq74mcxFqP48AkYwJDvehNxf+8XgbRtZ9zmWbAJJ0vijKBIcHTNnDIFaMgxoYQqrj5K6ZDoggF01nFlOAunrxM2vWae1Fz7y+rjfOijjI6RifoDLnoCjXQHWqiFqJogp7RK3qznqwX6936mEdLVjFziP7A+vwBzZCV1A==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
filter diffracts shorter 𝜆 out of the beam
𝜆/2dFilter>1
typically PG, Be, no 𝜆/2 filter needed for Si, Ge
(111) is used, because (222) is forbidden
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
sample environment cryostat, cryomagnet,
furnace, pressure cell, CryoPAD
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
sample environment cryostat, cryomagnet,
furnace, pressure cell, CryoPAD
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
collimator e.g. radial oscillating collimator
reduces background from sample environment or another Soller collimator to
increase resolution
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureBasic diffractometer (constant wavelength)
detector gas cells in which an incoming neutron triggers a nuclear reaction producing a charged particle which then is detected
typically 3He or B3F
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureTime-of-flight diffractometer (polychromatic)
chopper defines the wavelength band
avoids frame overlap
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureTime-of-flight diffractometer (polychromatic)
time of flight of the neutrons is related to the their wavelength
diffraction pattern is recorded at constant scattering angle
(close to 180° for best resolution, small Δt/t)
t =mn
h�L
<latexit sha1_base64="osfW5cVSy28rDyQU2Y5sFKxQsvs=">AAACA3icbVDLSsNAFJ34rPUVdaebwSK4kJKooBuh4MaFiwr2AU0Ik8mkHTozCTMToYSAG3/FjQtF3PoT7vwbp20W2npg4HDOPdy5J0wZVdpxvq2FxaXlldXKWnV9Y3Nr297Zbaskk5i0cMIS2Q2RIowK0tJUM9JNJUE8ZKQTDq/HfueBSEUTca9HKfE56gsaU4y0kQJ7X8Mr6MUS4ZwHosgHhcdMOkLwNrBrTt2ZAM4TtyQ1UKIZ2F9elOCME6ExQ0r1XCfVfo6kppiRoupliqQID1Gf9AwViBPl55MbCnhklAjGiTRPaDhRfydyxJUa8dBMcqQHatYbi/95vUzHl35ORZppIvB0UZwxqBM4LgRGVBKs2cgQhCU1f4V4gEwh2tRWNSW4syfPk/Zp3T2ru3fntcZJWUcFHIBDcAxccAEa4AY0QQtg8AiewSt4s56sF+vd+piOLlhlZg/8gfX5A1Q+l0A=</latexit>
��
�= �✓M cot ✓M
<latexit sha1_base64="QfGSYHdroUzdqCp7vz3sgbxAdEY=">AAACIXicbZBNS8NAEIY3flu/oh69BIvgQUqigr0Igh68CBWsCk0pk+2kXdx8sDsRSuhf8eJf8eJBkd7EP+O2pqCtLyw8vDPD7LxBKoUm1/20Zmbn5hcWl5ZLK6tr6xv25tatTjLFsc4Tmaj7ADRKEWOdBEm8TxVCFEi8Cx7Oh/W7R1RaJPEN9VJsRtCJRSg4kLFadtUPFfDcv0BJ4Esz2IZ+PobTwqcuErSufJ7QmFt22a24IznT4BVQZoVqLXvgtxOeRRgTl6B1w3NTauagSHCJ/ZKfaUyBP0AHGwZjiFA389GFfWfPOG0nTJR5MTkj9/dEDpHWvSgwnRFQV0/WhuZ/tUZGYbWZizjNCGP+syjMpEOJM4zLaQuFnGTPAHAlzF8d3gUTGZlQSyYEb/Lkabg9rHhHFe/6uHx2UMSxxHbYLttnHjthZ+yS1VidcfbEXtgbe7eerVfrwxr8tM5Yxcw2+yPr6xtoUKTR</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
D20 (high flux)
sample in a vanadium container V scatters only incoherently
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
Result: Diffraction pattern
0 20 40 60 80 100 120 140 1600
50
100
150
200
250
300
350
400
450
500
550
2θ (deg)
Inte
nsity
(cou
nts)
Useful information lies in the
‣ position
‣ the intensity
‣ the shape and width
of the reflections.
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
1. Position
Bragg’s law
monoclinic
orthorhombic
cubic
with 𝜃 and 𝜆 known → able to obtain lattice parameters and propagation vectors
n� = 2d sin ✓<latexit sha1_base64="Vd/2pnSIbmoOdQDLoyVZ3OmhtDI=">AAAB/nicbVDLSsNAFJ3UV62vqLhyM1gEF1KSKuhGKLhxWcE+oAllMpm0QyeTMHMjlFDwV9y4UMSt3+HOv3HaZqGtBwYO55zLvXOCVHANjvNtlVZW19Y3ypuVre2d3T17/6Ctk0xR1qKJSFQ3IJoJLlkLOAjWTRUjcSBYJxjdTv3OI1OaJ/IBxinzYzKQPOKUgJH69pH0hEmH5KYeeppLD4YMSN+uOjVnBrxM3IJUUYFm3/7ywoRmMZNABdG65zop+DlRwKlgk4qXaZYSOiID1jNUkphpP5+dP8GnRglxlCjzJOCZ+nsiJ7HW4zgwyZjAUC96U/E/r5dBdO3nXKYZMEnni6JMYEjwtAsccsUoiLEhhCpubsV0SBShYBqrmBLcxS8vk3a95l7U3PvLauO8qKOMjtEJOkMuukINdIeaqIUoytEzekVv1pP1Yr1bH/NoySpmDtEfWJ8/GGWVgA==</latexit> d =
✓h2
a2 sin2 �+
k2
b2+
l2
c2 sin2 �� 2hl cos�
ac sin2 �
◆� 12
<latexit sha1_base64="f5a4g2S5yDrr3+lIXqglbmjK4Gc=">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</latexit>
d =
✓h2
a2+
k2
b2+
l2
c2
◆� 12
<latexit sha1_base64="9xcUV3goiHGXoNTY534CBF3xzwk=">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</latexit>
d = a(h2 + k2 + l2)�12
<latexit sha1_base64="H0Y3Y6OvFJ3TADRHwy8R8sA4wlg=">AAACDnicbVDLSsNAFJ34rPUVdelmsBQqakmioBuh4MZlBfuANi2TyaQdOpmEmYlQQr7Ajb/ixoUibl2782+cpl1o64F7OZxzLzP3eDGjUlnWt7G0vLK6tl7YKG5ube/smnv7TRklApMGjlgk2h6ShFFOGooqRtqxICj0GGl5o5uJ33ogQtKI36txTNwQDTgNKEZKS32z7MNriCrDngNP4CjvrOcc99KzbiAQTu0sdbKsb5asqpUDLhJ7Rkpghnrf/Or6EU5CwhVmSMqObcXKTZFQFDOSFbuJJDHCIzQgHU05Col00/ycDJa14sMgErq4grn6eyNFoZTj0NOTIVJDOe9NxP+8TqKCKzelPE4U4Xj6UJAwqCI4yQb6VBCs2FgThAXVf4V4iHQMSidY1CHY8ycvkqZTtc+r9t1FqXY6i6MADsERqAAbXIIauAV10AAYPIJn8ArejCfjxXg3PqajS8Zs5wD8gfH5A3GbmTA=</latexit>
d = a⇥(h+ qx)
2 + (k + qy)2 + (l + qz)
2⇤� 1
2
<latexit sha1_base64="IWuioxMD+K0WiwGhbnWeenCzyVE=">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</latexit>
Magnetic Bragg reflections can be found at k = G± q<latexit sha1_base64="pvnua7XFfnAuwies5n4jD3WM3tI=">AAACDHicbVDLSsNAFL3xWeur6tLNYBFcSElU0I1QcKHLCvYBbSiT6aQdOpnEmYlQQj7Ajb/ixoUibv0Ad/6NkzYFbT0wcOace7n3Hi/iTGnb/rYWFpeWV1YLa8X1jc2t7dLObkOFsSS0TkIeypaHFeVM0LpmmtNWJCkOPE6b3vAq85sPVCoWijs9iqgb4L5gPiNYG6lbKncCrAeenwzTyym9TjtRgKa/+9RU2RV7DDRPnJyUIUetW/rq9EISB1RowrFSbceOtJtgqRnhNC12YkUjTIa4T9uGChxQ5SbjY1J0aJQe8kNpntBorP7uSHCg1CjwTGW2oZr1MvE/rx1r/8JNmIhiTQWZDPJjjnSIsmRQj0lKNB8ZgolkZldEBlhiok1+RROCM3vyPGmcVJzTinN7Vq4e53EUYB8O4AgcOIcq3EAN6kDgEZ7hFd6sJ+vFerc+JqULVt6zB39gff4AxymcAQ==</latexit>
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
2. Intensity
nuclear structure factor (interaction between neutron and core potential of nuclei)
magnetic structure factor (interaction between neutron and electron’s magnetic field)
0.2 0.4 0.6 0.8 1 1.2 1.4
0.2
0.4
0.6
0.8
1
sinθ/λ
f
magnetic form factor
I ⇠ F 2<latexit sha1_base64="UFgnjSihrWoztB7rw4xLgRG7bTQ=">AAAB8HicbVBNSwMxEJ2tX7V+VT16CRbBg5TdVtBjQRC9VbAf0q4lm2bb0CS7JFmhLP0VXjwo4tWf481/Y9ruQVsfDDzem2FmXhBzpo3rfju5ldW19Y38ZmFre2d3r7h/0NRRoghtkIhHqh1gTTmTtGGY4bQdK4pFwGkrGF1N/dYTVZpF8t6MY+oLPJAsZAQbKz3cdjUT6Pqx0iuW3LI7A1omXkZKkKHeK351+xFJBJWGcKx1x3Nj46dYGUY4nRS6iaYxJiM8oB1LJRZU++ns4Ak6sUofhZGyJQ2aqb8nUiy0HovAdgpshnrRm4r/eZ3EhJd+ymScGCrJfFGYcGQiNP0e9ZmixPCxJZgoZm9FZIgVJsZmVLAheIsvL5NmpexVy97deal2lsWRhyM4hlPw4AJqcAN1aAABAc/wCm+Ocl6cd+dj3ppzsplD+APn8wfAc4+l</latexit> f(k) =
1Z
�1
⇢mag(r) exp(ikr)dr
<latexit sha1_base64="ulv1Y4LHAidWYqhlW0G2dTHJEb0=">AAACUHicbVFLSwMxEJ6t7/qqevQSLEIFLbsq6EUQvHhUsCp065JNs21oNrsks2JZ9id68ebv8OJB0fTh24GQL983M5l8CVMpDLruo1OamJyanpmdK88vLC4tV1ZWL02SacYbLJGJvg6p4VIo3kCBkl+nmtM4lPwq7J0M9Ktbro1I1AX2U96KaUeJSDCKlgoqnajmxxS7YZT3iq0jXyj0pYgFmiDfsacI+8XNaCe+7iZBbhsUnzW62PL5XVoTX02+Se0vHFSqbt0dBvkLvDGowjjOgsqD305YFnOFTFJjmp6bYiunGgWTvCj7meEpZT3a4U0LFY25aeVDQwqyaZk2iRJtl0IyZL9X5DQ2ph+HNnMwofmtDcj/tGaG0WErFyrNkCs2uijKJMGEDNwlbaE5Q9m3gDIt7KyEdammDO0flK0J3u8n/wWXu3Vvr+6d71ePt8d2zMI6bEANPDiAYziFM2gAg3t4ghd4dR6cZ+et5IxSP3ZYgx9RKr8DeWy3ig==</latexit>
FM (k) =X
j
µjfj(k) exp(ikrj) exp
✓�Bj
sin2 ✓
�2
◆
<latexit sha1_base64="9fG5doPyngNDElRcw/SfuPSiynY=">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</latexit>
FN (k) =X
j
bj exp(ikrj) exp
✓�Bj
sin2 ✓
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T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
3. Peak width and shape
2θM 2θM 2θM
source, monochromator, slits, collimators, sample strain, stress, correlation length etc. have an influence on the peak shape and the peak width
Caglioti formula
resolution function minimum at the take-off angle 2𝜃M
(focussing effect)
FWHM2= u tan2 ✓ + v tan ✓ + w
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T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedurePowder diffraction
Thermodiffraction
Collection of diffraction patterns as a function of temperature. Clearly reveals structural and magnetic phase transitions.
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureSingle crystal diffraction - 4-circle geometry
by adjusting 2𝜃, 𝜔, 𝜒 and 𝜙
the sample is put in reflection position
D10 (ILL)
single crystal on Al pin
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureSingle crystal diffraction - Normal beam geometry
cryomagnets, pressure cells, … cannot be tilted much
→ confined to the scattering plane e.g. only (hk0) reflections
→ lifting counter able to reach l=1, 2…
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureSingle crystal diffraction - Laue method
polychromatic beam → every accessible hkl plane is in reflection position for a particular wavelength
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
Experimental procedureSingle crystal diffraction - Laue method
‣ quickly orient single crystals
‣ observe phase transitions
‣ magnetic satellites
‣ find propagation vectors
‣ structure analysis also possible
T H E E U R O P E A N N E U T R O N S O U R C E16th Oxford School on Neutron Scattering | Navid Qureshi
SummaryDiffraction from magnetic materials
‣ magnetic scattering is comparable in intensity to nuclear scattering
‣ Only the component of the magnetic moment perpendicular to the scattering vector is measurable
‣ The magnetic form factor is the Fourier transform of the atomic magnetisation density
‣ The magnetic structure factor is the Fourier transform of the unit cell magnetisation density
‣ We measure phase information is lost models necessary
‣ How dow we get those models? See you tomorrow
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