First principles studies of GeTe based dilute magnetic semiconductors

T. Fukushima, H. Shinya, H. Fujii, K. Sato, H. Katayama-Yoshida, P. H. Dederichs

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The electronic structure and magnetic properties of GeTe-based dilute magnetic semiconductors (DMS) are investigated by the Korringa - Kohn - Rostoker Green's function method and the projector augmented wave method. Our calculations for the formation energies of transition metal impurities (TM) in GeTe indicate that the solubilities of TM are quite high compared to typical III - V and II - VI based DMS and that the TM doped GeTe has a possibility of room temperature ferromagnetism with high impurity concentrations. The high solubilities originate from the fact that the top of the valence bands of GeTe consists of the Te-5p anti-bonding states which are favorable to acceptor doping. (Ge, Cr)Te system shows strong ferromagnetic interaction by the double exchange mechanism and is a good candidate for DMS with high Curie temperature. Additionally, in the case of (Ge, Mn)Te with the d5configuration, by introducing the Ge vacancies the p-d exchange interaction is activated and it dominates the antiferromagnetic superexchange, resulting in ferromagnetic exchange interactions between Mn. This explains recent experimental results reasonably. Based on the accurate estimation of the Curie temperatures by Monte Carlo simulation for the classical Heisenberg model with the calculated exchange coupling constants, we discuss the relevance of the TM doped GeTe for semiconductor spintronics.

Original languageEnglish
Article number015501
JournalJournal of Physics Condensed Matter
Volume27
Issue number1
DOIs
Publication statusPublished - 2014 Jan 14
Externally publishedYes

Keywords

  • Dilute magnetic semiconductor
  • Korringa - Kohn - Rostoker method
  • Semiconductor spintronics

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'First principles studies of GeTe based dilute magnetic semiconductors'. Together they form a unique fingerprint.

  • Cite this