Magnetic and electronic structure of (Ga1-xMnx)As
2003 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 67, no 20, 205201- p.Article in journal (Refereed) Published
We present theoretical calculations of the magnetic and electronic structure of Mn-doped GaAs (in the zinc-blende structure). The magnetic properties are shown to be very sensitive to structural defects, in particular, As antisite defects and Mn at interstitial positions. Only when considering such defects can the experimental magnetic moments be reproduced by first-principles theory. We present a simple model for understanding the connection between the magnetic ordering and the As antisites, and the way in which the defects help to stabilize a partial disordered local-moment state. The connection between the energetics of the Mn substitution and the As antisite concentration is also analyzed. In addition, we compare the calculated magnetic properties and electronic structures of Mn situated on substitutional sites (Mn replacing a Ga atom) and on interstitial sites, where in agreement with observations the interstitial site is found to be less favorable. Finally, combining our first-principles calculations of the spin-wave excitation energies with a classical Heisenberg Hamiltonian we have calculated interatomic exchange interactions, and using Monte Carlo simulations we present theoretical values of the critical temperature as a function of Mn concentration.
Place, publisher, year, edition, pages
2003. Vol. 67, no 20, 205201- p.
point-defects, ferromagnetism, metals, alloys, gaas, energy, ni, semiconductors, temperature, co
Condensed Matter Physics Other Materials Engineering
IdentifiersURN: urn:nbn:se:kth:diva-22579DOI: 10.1103/PhysRevB.67.205201ISI: 000183483200028OAI: oai:DiVA.org:kth-22579DiVA: diva2:341277
QC 20100525 NR 201408042010-08-102010-08-102012-02-13Bibliographically approved