Advanced tetrahedrally-bonded magnetic semiconductors for spintronic applications

Arthur J Freeman, Yu Jun Zhao

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)1453-1459
Number of pages7
JournalJournal of Physics and Chemistry of Solids
Volume64
Issue number9-10
DOIs
Publication statusPublished - Sep 2003

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Keywords

  • A Semiconductors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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