TY - JOUR
T1 - Advanced tetrahedrally-bonded magnetic semiconductors for spintronic applications
AU - Freeman, A. J.
AU - Zhao, Yu Jun
N1 - Funding Information:
Work supported by DARPA/ONR (grant No.: N00014-02-1-0887) and grants of computer time at the NAVO and ERDC Supercomputing Centers. The authors thank Dr Picozzi, Dr Shishidou for their helps and discussions.
PY - 2003/9
Y1 - 2003/9
N2 - Recent developments of magnetic semiconductors suggest the possibility of harnessing the spin of the electron - in addition to its charge - for future devices and some examples are given here. Highly precise FLAPW calculations demonstrate that: (i) Cd1-xMnxGeP2 chalcopyrites are antiferromagnetically (AFM) favored but will undergo a phase transition to the FM state with n-type S doping. Hence, the magnetic moments (mm) may be tuned with impurities, and a great boon for technological applications; (ii) a new class of half-metallic ferromagnetic semiconductors in Mn doped I-III-VI2 chalcopyrites is predicted with the Curie temperature TC proportional to the hole concentration. Moreover, we investigated the electronic and magnetic properties of MnxGe 1-x as a function of Mn positions in a 64 atom supercell. The FM aligned Mn at a distance of a2 has the lowest energy, followed by several energetically competitive FM and AFM configurations, explaining the observation of 'inactive' Mn mm, and the theoretical mm of 3.0μB per Mn for the FM states. Surprisingly, the exchange interaction between a Mn pair is found to oscillate with the distance between them, and to obey the RKKY analytic formula. In addition, the estimated TC, around 134-400 K, is in good agreement with experiment.
AB - Recent developments of magnetic semiconductors suggest the possibility of harnessing the spin of the electron - in addition to its charge - for future devices and some examples are given here. Highly precise FLAPW calculations demonstrate that: (i) Cd1-xMnxGeP2 chalcopyrites are antiferromagnetically (AFM) favored but will undergo a phase transition to the FM state with n-type S doping. Hence, the magnetic moments (mm) may be tuned with impurities, and a great boon for technological applications; (ii) a new class of half-metallic ferromagnetic semiconductors in Mn doped I-III-VI2 chalcopyrites is predicted with the Curie temperature TC proportional to the hole concentration. Moreover, we investigated the electronic and magnetic properties of MnxGe 1-x as a function of Mn positions in a 64 atom supercell. The FM aligned Mn at a distance of a2 has the lowest energy, followed by several energetically competitive FM and AFM configurations, explaining the observation of 'inactive' Mn mm, and the theoretical mm of 3.0μB per Mn for the FM states. Surprisingly, the exchange interaction between a Mn pair is found to oscillate with the distance between them, and to obey the RKKY analytic formula. In addition, the estimated TC, around 134-400 K, is in good agreement with experiment.
KW - A Semiconductors
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U2 - 10.1016/S0022-3697(03)00120-3
DO - 10.1016/S0022-3697(03)00120-3
M3 - Article
AN - SCOPUS:0042236951
SN - 0022-3697
VL - 64
SP - 1453
EP - 1459
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
IS - 9-10
ER -