Do As antisites destroy the ferromagnetism of (Ga,Mn)As?

Fuente: arXiv
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Autori principali: Sanvito, Stefano, Hill, Nicola A.
Natura: Preprint
Pubblicazione: 2000
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author Sanvito, Stefano
Hill, Nicola A.
author_facet Sanvito, Stefano
Hill, Nicola A.
contents The effect of the inclusion of As antisites in the diluted magnetic semiconductor (Ga,Mn)As is studied within density functional theory in the local spin density approximation. In the case of homogeneous distribution of Mn ions we find that the ferromagnetism is largely weakened by the presence of the antisites. This is due to compensation of the free holes which mediate the long range ferromagnetic order. In contrast, when two Mn ions are coupled through only one As ion, ferromagnetic and antiferromagnetic order compete. In this case the magnetic ground state depends on: i) the position of the As antisites relative to the Mn, and ii) the As antisite concentration. We explain our results using a model of competing antiferromagnetic super-exchange and ferromagnetic double-exchange via localized Zener carriers. The strong dependence of the ferromagnetic order on the microscopic configuration accounts for the large variation in experimental data
format Preprint
id arxiv_https___arxiv_org_abs_cond_mat_0011372
institution arXiv
publishDate 2000
record_format arxiv
spellingShingle Do As antisites destroy the ferromagnetism of (Ga,Mn)As?
Sanvito, Stefano
Hill, Nicola A.
Materials Science
Mesoscale and Nanoscale Physics
The effect of the inclusion of As antisites in the diluted magnetic semiconductor (Ga,Mn)As is studied within density functional theory in the local spin density approximation. In the case of homogeneous distribution of Mn ions we find that the ferromagnetism is largely weakened by the presence of the antisites. This is due to compensation of the free holes which mediate the long range ferromagnetic order. In contrast, when two Mn ions are coupled through only one As ion, ferromagnetic and antiferromagnetic order compete. In this case the magnetic ground state depends on: i) the position of the As antisites relative to the Mn, and ii) the As antisite concentration. We explain our results using a model of competing antiferromagnetic super-exchange and ferromagnetic double-exchange via localized Zener carriers. The strong dependence of the ferromagnetic order on the microscopic configuration accounts for the large variation in experimental data
title Do As antisites destroy the ferromagnetism of (Ga,Mn)As?
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/cond-mat/0011372