物理システム工学科3年次 物性工学概論 第火曜1限 0035 教室 第 12...
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物理システム工学科3年次 物性工学概論 第火曜1限 0035 教室 第 12 回 スピンエレクトロニクスと材料 [2] 磁性の起源・磁気記録. 副学長 佐藤勝昭. 磁性体を特徴づけるもの (1) 磁気ヒステリシス. 縦軸:磁化. 強磁性体においては、その磁化は印加磁界に比例せず、ヒステリシスを示す。. O→B→C: 初磁化曲線 C→D: 残留磁化 D→E: 保磁力 C→D→E→F→G→C: ヒステリシスループ. 横軸:磁界. ( 高梨:初等磁気工学講座テキスト ). 磁性体を特徴づけるもの (2) 自発磁化の温度変化. - PowerPoint PPT PresentationTRANSCRIPT
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003512[2]
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(1)()OBC:CD: DE: CDEFGC:
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(2)TcTc
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HcHcHc
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(BH)max (http://www.aacg.bham.ac.uk/magnetic_materials/history.htm)
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()3d4f
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3d Fe, Co, NiMn (MnAs, MnSb, MnBi, MnAl, MnGa, Mn5Ge3, PtMnBi), Cr (CrO2, Cr3Te4, CdCr2Se4)4fGd, Dy
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3dTi V Cr () TN=308KMn() TN=100K@RTFe m=2.219 B/atom Tc=1043KCo m=1.715 B/atom Tc=1388KNi m=0.604 B/atom Tc=631KCu
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4fGd3d
SmCo5NdFe2B14GdCoTbFe
Ce12.5Pr25Nd19Sm14.8Eu90Gd293Tb222229Dy85179Ho20131Er2084
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(Wb/cm2) HPhttp://www.magnet.okayama-u.ac.jp/magword/domain/
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-e[C]a[m]v[m/s] 2a/v[s] i=-ev/2a[A]i S= a2 =iS=-eav/2=mav =-(e/2m) N
S
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l=LL=-(e/2m) l=-(e/2m)L=- BL B=e/2m =9.2710-24[J/T][J/T]=[Wb2/m]/[Wb/m2]=[Wbm]
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s1/2sz1/2 s=ss=-(e/m)ss=-(e/m)s=- 2Bs2g(g=2.0023) s=- gBs
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Na()D
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NaDD13s1/23p1/2D23s1/23p3/2http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/sodzee.html#c3
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n=1 K-shelln=2 L-shelln=3 M-shell1s 22s, 2p 2+63s, 3p, 3d 2+6+10=18
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nl=n-1, .... ,0
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s, p, d, fl=0, 1, 2, 3s0
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L, S(n, l, ml, ms)1(Pauli)SLsl(Hund1)S(Hund2)Jless than halfJ=|L-S| more than halfJ=L+S
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3d4f
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()()() MM=( n- n)B
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TcTCTN
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M-TJS=1/2,1,
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(demagnetization field)Mn = Mn(Wb/m2) /0NNMM
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N (Nx, y, zNx, Ny, NzHdi=-NiMi/0 (i=x,y,z)Nx, Ny, NzNx+ Ny+ Nz=1Nx= Ny= Nz=1/3zNx= Ny= 1/2Nz=0Nx= Ny= 0Nz=1 Heff=Hex-NM/0 xyzzxyzxyNz=1Nx= 0Ny= 0Nx= 1/2Ny= 1/2Nx=1/3Ny=1/3Nz=1/3Nz=0
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MHd U=MHdHMT T=-MH sinEU=Td= - 0MH sin d=MH (1-cos) U=-MH H=-Hd U=MHd
- xyz=0zxd =Is 2md
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()
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[100][111]xyz[111][100][110]
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(magnetic domain)NS
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(Fe[001])[001](001)[100][010][-100][0-10]90[111]()
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WeissP.Weiss: J. Phys. 6, 661 (1907)H. Barkhausen: Phys. Z. 20, 401 (1919)
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micromagnetics[W.F.Brown, Jr.; J. Appl. Phys. 11, 160 (1940), Phys. Rev. 58, 736 (1940) ]UmagUexUaUelU=Umag+Uex+Ua+Uel
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Gyromagnetic constant: Damping constantHeff: Effective fieldMs: Saturation magnetizationMs=|M|,
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Micromagnetic simulation using LLG Hy = 10 kOe 0 Oe divMdivMy Dot model
Saturation magnetization (Ms)800 emu/cm3Exchange field (A)110-6 erg/cm3Anisotropic constant (Ku)1000 erg/cm3Gyro magnetic constant)-1.76107 rad/(sOe)Damping constant0.2Easy axisY directionDot Size200 nm200 nm100 nmNumber of dot1Mesh size10 nm10 nm10 nm
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200 x 200 x t50 nm- dv M200 x 200 x t100 nm
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Force gradient imageSpin distribution image
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Low-moment tip(CoPtCr/240 in HV)High-moment tip(CoPtCr/500 in Air)Spin distribution imageMFM
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Hy = 10 kOe 0 Oe Dot modeldivMdivMy
Saturation magnetization (Ms)800 emu/cm3Exchange field (A)110-6 erg/cm3Anisotropic constant (Ku)1000 erg/cm3Gyro magnetic constant)-1.76107 rad/(sOe)Damping constant0.2Easy axisY directionDot Size200 nm200 nm100 nmNumber of dot1Mesh size10 nm10 nm10 nm
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Dot model
Graph3
792.108035
761.845559
560
205.70034
111.242521
31.31431
10.901125
-9.698591
-95.156627
-221.06158
-560
-761.780267
-796.814957
-761.780262
-580
-206.635844
-111.24205
-31.314309
-10.901066
E.A.
H (Oe)
M (emu/cc)
testHy
TitleHx(Oe)Hy(Oe)Hz(Oe)|H|(Oe)Mx(emu/cc)My(emu/cc)Mz(emu/cc)|M|(emu/cc)
test-Hy10000.0100000100000792.1080350792.108035
test-Hy5000.05000050000761.8455590761.845559
3000560
test-Hy1000.01000010000.193714205.70034-0.361489205.700749
test-Hy500.050005000111.2425210111.242521
test-Hy100b.01000100031.31431031.31431
test-Hy0.0000010.901125010.901125
test-Hy-100.0-10001000-9.69859109.698591
test-Hy-500.0-50005000-95.156627095.156627
test-Hy-1000.0-1000010000-221.061580221.06158
-3000-560
test-Hy-5000.0-5000050000-761.7802670761.780267
test-Hy-10000.0-100000100000-796.8149570796.814957
test-Hy_-10k_-5k.0-5000050000-761.7802620761.780262
-3000-580
test-Hy_-10k_-1k.0-1000010000.000155-206.635844-0.000024206.635844
test-Hy_-10k_-5000-5000500-0.000016-111.24205-0.000007111.24205
test-Hy_-10k_-1000-10001000-31.314309031.314309
test-Hy_-10k_000000-10.901066010.901066
Ms800
Ku1000
Hk2.5
Hk=2Ku/Ms
testHy
E.A.
H (Oe)
M (emu/cc)
H (Oe)
M (emu/cc)
Graph1
792.108035
761.845559
560
205.70034
111.242521
31.31431
10.901125
-9.698591
-95.156627
-221.06158
-560
-761.780267
-796.814957
-761.780262
-580
-206.635844
-111.24205
-31.314309
-10.901066
H (Oe)
M (emu/cc)
P1-Crs
TitleHx(Oe)Hy(Oe)Hz(Oe)|H|(Oe)Mx(emu/cc)My(emu/cc)Mz(emu/cc)|M|(emu/cc)
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz20k00200002000000798.8078661797747.318844
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz10k00100001000000794.012011787106.133157
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz5k00500050000.933771-8.07547680.0378711531397.331096
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz1k0010001000-0.1029510.186052174.124484393007.993059
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz0000000-0.09572219127.439362
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz_-50000-50050000-79.241447180525.944069
P1-Crs_L500n-W100n-t50n_10x10x10_a02_Hz_-1k00-1000100000-174.142919393049.521032
P1-Crs
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=m+w
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18090
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(demagnetization field)HM
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FIBCoCrPt(500nm)MFM (M)CoCrPt
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(vortex)(200nm)MFM ()
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(closure domain)(1m)MFM (M2)D2 MFM
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MFM()(Fe20Ni80) (M)
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FIBCo ()200nm1m, 200nm
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(magnetic recording)
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1898V.Poulsen()19001921L.De Forest()1930
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(, 1991)5.18
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)=v/f (v:, f:)
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E()(, 1991)5.19, 5.20
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2MR()(MR:)AMR()90GMR()
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GMRF1F2GMR(SV)
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GMR()(F)/(N)/(F2)F1, F2
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NiFe(free)/Cu/NiFe(pinned)/AF(FeMn) ( FeMn)SAF
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HDHD1992MR25%(1010)60%(10100)1997GMR100%(101000)40Gb/in2AFC()2003150 Gb/in22004200 Gb/in2
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HDHD1992MR25%(1010)60%(10100)1997GMR100%(101000)40Gb/in2AFC()2003150 Gb/in22004200 Gb/in2
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197019901010199010100100Gb/in22000
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CoCrTaCo
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nmCoCrCr 10 nm
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CoCrPtBCoCrCoCrCrKuV (KuV)kT
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20 Gb/in210 nmp.97(2003)
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=KuV/kT>60MSJp.97(2003)
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=KuV/kT>60DdD-1/2Vd3VDD-3/2KuHcHc=2Ku/MsD3/2[1]Hc [1] T.W. McDaniel and W.A. Challener: Proc. MORIS2002, Trans Magn. Soc. Jpn. 2 (2002) 316.
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AFC()AFC(antiferromagnetically coupled media)RuVSF(synthetic ferromagnet)
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(AFC)AFC
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500Gbits/in21/2
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HcHc
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HDDCoCrMOMOPt/CoHcHc
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CoCrPt layerresist grooveby imprinting80nm-pitch, 40nmf()