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Magnetic semiconductors in ternary Cd–Mn–Te compounds
Author(s) -
Liu Yong,
Liu BangGui
Publication year - 2008
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200743422
Subject(s) - superexchange , antiferromagnetism , magnetic semiconductor , ferromagnetism , semiconductor , condensed matter physics , magnetic moment , ternary operation , cadmium telluride photovoltaics , chemistry , materials science , physics , nanotechnology , optoelectronics , computer science , programming language
Since Mn‐doped CdTe in zincblende structure has been fabricated for Mn concentrations from 0 to 0.5, we use a first‐principles full‐potential method to study CdTe‐based ternary Cd–Mn–Te compounds for possible magnetic semiconductors. The compounds are constructed by substituting Mn for some Cd atoms in zincblende CdTe. We optimize fully their geometric structures and internal atomic positions, and then study their electronic and magnetic properties. We find that the stable CdMnTe 2 and Cd 3 MnTe 4 are antiferromagnetic semiconductors with space groups 160 and 111, and the stable Cd 7 MnTe 8 is a layered ferromagnetic semiconductor with space group 115. Their real lattice constants are a little smaller than CdTe's and an Mn atom contributes 5 Bohr magnetons to their total magnetic moments. The antiferromagnetism for the CdMnTe 2 is attributed to the Te‐based superexchange of Mn spins. For the other two, the MnMn spin interactions are dependent on the MnMn distance and the environment. The antiferromagnetism for the Cd 3 MnTe 4 and the layered ferromagnetism for the Cd 7 MnTe 8 can be attributed to two weaker indirect exchange interactions based on both Cd and Te. The Kohn–Sham gaps of the three magnetic semiconductors are 0.52 eV, 0.80 eV, and 1.23 eV, respectively. The real semiconductor gaps may be larger than 1 eV considering the fact that the Kohn–Sham gap of CdTe is 0.55 eV but the experimental semiconductor gap is 1.56 eV at 300 K. These magnetic semiconductors, compatible with semiconductors such as CdTe, could be useful in spintronics applications. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)