Half-metallic ferromagnetism in hexagonal MAl7N8 and cubic MAl3N4 (M=Cr and Mn) from first principles

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	Half-metallic ferromagnetism in hexagonal MAl7N8 and cubic MAl3N4 (M=Cr and Mn) from first principles
	Shi, LJ ; Liu, BG
刊名	PHYSICAL REVIEW B
	2007
卷号	76 期号:11
ISSN号	1098-0121
中文摘要	Motivated by recent reports on high Curie temperatures in Cr- and Mn-doped aluminum nitrides and the fabrication of heavily transition-metal-doped ones with room-temperature ferromagnetism, we study systematically 12.5% transition-metal substituted aluminium nitrides, hexagonal CrAl7N8 and MnAl7N8, using a full-potential density-functional method. We optimize fully the crystal structures and prove the stability of their ferromagnetism against possible antiferromagnetic orders. Their volumes are expanded only by about 1% compared with that of AlN. Every d electron of +3 cations of Cr and Mn contributes one Bohr magneton to the moment. Our calculations show that both of them are half-metallic ferromagnets with half-metallic gaps larger than 1 eV. The transition-metal substitution creates 10 transition-metal d-dominated impurity bands in the semiconductor gap of AlN. The hybridization of the d states with the N p ones yields a large spin exchange splitting of the d states which drives the ferromagnetism. The half-metallicity is attributed to the wide minority-spin gap across the Fermi level and the favorable majority-spin density of states of the d-dominated bands in addition to the above factors. 25% Cr and Mn substituted cubic aluminum nitrides, cubic CrAl3N4 and MnAl3N4, are studied in the same way and proved to share almost all the properties of the two hexagonal ones. The mechanism for the ferromagnetism should be useful for understanding nitride-based diluted magnetic semiconductors. These half-metallic transition-metal aluminum nitrides, at least some of them, could be useful in spintronics.
收录类别	SCI
公开日期	2013-09-17
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/39046]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Shi, LJ,Liu, BG. Half-metallic ferromagnetism in hexagonal MAl7N8 and cubic MAl3N4 (M=Cr and Mn) from first principles[J]. PHYSICAL REVIEW B,2007,76(11).
APA	Shi, LJ,&Liu, BG.(2007).Half-metallic ferromagnetism in hexagonal MAl7N8 and cubic MAl3N4 (M=Cr and Mn) from first principles.PHYSICAL REVIEW B,76(11).
MLA	Shi, LJ,et al."Half-metallic ferromagnetism in hexagonal MAl7N8 and cubic MAl3N4 (M=Cr and Mn) from first principles".PHYSICAL REVIEW B 76.11(2007).