research project in magnetism & spin electronics · would enable the creation of spin-based...
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Research project in Magnetism & Spin Electronics
Research supervisor: Dr. Plamen StamenovMagnetism & Spin Electronics
Magnetic Semiconductors: p-n Junctions and Magnetic Bipolar Heterojunction Transistors
Research project in Magnetism & Spin Electronics
Magnetism & Spin ElectronicsScientific Background / Current Research
Magnetic Semiconductors are a class of materials that utilize the versatility andfunctionality of semiconductors, and take advantage of the spin degree of freedom, inorder to enable key applications in modern spin electronics (not to be confused with therather controversial class of Dilute Magnetic Semiconductors). The realisation of activeelectronic components with net spin gain is a ‘holy grail’ of spin electronics research, as itwould enable the creation of spin-based logic gates and further development ofcomponents such as non-volatile programmable logic and storage arrays, among others.Magnetic-semiconductor-based devices are one of the ways forward.
ProjectProject
The project will involve the synthesisand characterisation of bulk ferro-,ferri- and antiferromagneticsemiconducting systems (such asCuCrO :Mg and CdCr Se ) and theCuCrO2:Mg and CdCr2Se4) and thesubsequent deposition of multi-layers stacks by Pulsed LaserDeposition (see diagram on theright), in collaboration with the groupof Prof. J. Lunney, and the formationf di d d t i t t t
Schematic of the PLD tool used for thin film deposition (left) and an actual plasmaplume within the system (right).. Image courtesy of J. Alaria and M. K. O’Sullivan
The magneto-conductance of athin film of CuCrO2:Mg in high field(up to 14 T) at varioustemperatures, both below and
200
250
300
T (K) 2 5 10 50 100an
ce M
C, %
of diode and transistor structures.The devices will be characterisedusing a variety of experimentaltechniques, including the use of highmagnetic field transport, andsynchrotron and neutron radiation.
above the antiferromagnet-paramagnet transition (TN ~ 25 K).Note the very high magnitude ofthe effect (> 300 %) at lowtemperatures.
Al / Au
ZnO:Al
-14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14
0
50
100
150
150 200 250 300
Mag
neto
cond
ucta
Magnetic Field 0H, T
Schematic structure of themagnetic bipolar heteroj nction
Funding
Funding for this project has been approved and is available through the School of Physics and CRANN, TCD. Contact detailst l @t d i R SNIAM 0 08 t l 353 1 896 2171
Al2O3
CuCrO2:Mgmagnetic bipolar heterojunctiontransistors prepared by PLDwith the use of in-situ shadowmasking.
© School of Physics, TCD, 2011
[email protected] Room no.: SNIAM 0.08 tel. +353 1 896 2171
More information / References• M. E. Flatté, Z. G. Yu, E. J-Halperin and D. D. Awschalom, Appl. Phys. Lett. 82, 4740 (2003).• J. Fabian,I. Zutić, and S. Das Sarma, Phys. Rev. B. 66, 165301 (2002).• http://www.tcd.ie/Physics/People/Plamen.Stamenov