Electronic structure and magnetism of diluted magnetic semiconductors
2004 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 16, no 48, S5481-S5489 p.Article in journal (Refereed) Published
The electronic structure and magnetism of selected diluted magnetic semiconductors (DMS) is reviewed. It is argued that the effect of antisite defects plays an important role in the magnetism of DMS materials and that these defects lower the saturation moment and ordering temperature. We also show that the interatomic exchange of these materials is short ranged. By combining first principles calculations of interatomic exchange interactions with a classical Heisenberg model and Monte Carlo simulations, we show that-the observed critical temperatures of a broad range of diluted magnetic semiconductors, involving Mn-doped GaAs and GaN as well as Cr-doped ZnTe, are reproduced with good accuracy. We show that agreement between theory and experiment is obtained only when the magnetic atoms are randomly positioned on the Ga (or Zn) sites. This suggests that the ordering of DMS materials is heavily influenced by magnetic percolation and that the measured critical temperatures should be very sensitive to details in the sample preparation, in agreement with observations.
Place, publisher, year, edition, pages
2004. Vol. 16, no 48, S5481-S5489 p.
ferromagnetism, temperature, metals
Materials Engineering Physical Chemistry
IdentifiersURN: urn:nbn:se:kth:diva-39716DOI: 10.1088/0953-8984/16/48/002ISI: 000226025300003ScopusID: 2-s2.0-10444284246OAI: oai:DiVA.org:kth-39716DiVA: diva2:444701
1st International Conference on Nanospintronics Design and Realization (ICNDR 2004). Kyoto, JAPAN. MAY 24-28, 2004
QC 201109292011-09-292011-09-122016-05-09Bibliographically approved