W形六角铁氧体BaFe<sub>18</sub>O<sub>27</sub>电子结构与导电性的第一性原理研究

doi:10.7498/aps.60.107102

摘要
参考文献(15)
相关文章 (15)

全文: PDF (1902 KB) HTML (0 KB) 导出: BibTeX | EndNote (RIS) Supporting Info

摘要：

采用基于第一性原理的GGA+U方法研究了BaFe₁₈O₂₇的晶体结构和基态电子结构. 以实验数据为初始结构的离子弛豫显示,由于稳定结构中离子半径的差异和2d位Fe的存在,位于BaO层中6h位的O离子脱离了实验结构中原胞的"表面"位置,产生畸变. 计算得到晶体磁矩为28 μ_B/f.u.,与实验相符. 电子态密度及能带计算表明该材料具有微弱的半金属特性,而且与c轴平行方向和垂直方向的能带色散关系有着很大不同,6g位Fe在该材料的输运特性中起着关键作用,它们形成一种"导电层",导致垂直电导率和平行电导率出现非常大的差异.

关键词：第一性原理 W形六角铁氧体电子结构导电性

	服务

	把本文推荐给朋友
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	李忠虎
	李林
	朱林

Abstract：

The electronic ground state and the electric conductivity of W-type hexagonal ferrite BaFe₁₈O₂₇ are investigated in the generalized gradient approximation (GGA) as well as the GGA plus Hubbard U(GGA+U) scheme. The ionic relaxation calculation of the experimental crystal structure shows that oxygen ions at 6h site in the BaO layer move away from the "surface" position in the unit cell, resulting in a structural distortion. The magnetic moment of the cell is calculated to be 28 μ_B/f.u., in agreement with previous experimental results. By taking account of electronic band structure and crystal ionic configuration it is found that the material is a weak half-metal and the effective mass of conduction electrons along the c axis is much heavier than that perpendicular to this axis. Fe ions on octahedral 6 g sites and O ions around them of the spinel block form a "conductive layer". Therefore the electric conductivity perpendicular to the c axis is much greater than that parallel to the c axis.

Keywords： first-principles W-type hexagonal ferrite electronic structure electric conductivity

收稿日期: 2010-11-09 出版日期: 2011-10-15

PACS:	71.15.Mb	(Density functional theory, local density approximation, gradient and other corrections)
	75.50.Gg	(Ferrimagnetics)
	72.80.Ga	(Transition-metal compounds)

基金:

辽宁省计划科学基金(批准号:2006222002)资助的课题.

引用本文:

李忠虎,李林,朱林. W形六角铁氧体BaFe₁₈O₂₇电子结构与导电性的第一性原理研究. 物理学报, 2011, 60(10): 107102.

Cite this article:

Ri Chung-Ho,Li Lin,Zhu Lin. First-principles study of the electronic structure and electric conductivity in W-type hexagonal ferrite BaFe₁₈O₂₇. Acta Phys. Sin., 2011, 60(10): 107102.

URL:

http://wulixb.iphy.ac.cn/CN/Y2011/V60/I10/107102 或 http://wulixb.iphy.ac.cn/CN/10.7498/aps.60.107102

References

[1]	Li Z W, Lin G Q, Wu Y P, Kong L B 2009 J. Phys. D 42 095007
[2]	Vmit Özgür, Yahya Alivov, Hadis Morko 2009 J. Mater. Sci: Mater Electron 20 789
[3]	Harris V G, Geiler A, Chen Y J, Yoon S D, Wu M Z, Yang A, Chen Z H, He P, Parimi P V, Zuo X, Patton C E, Abe M, Acher O, Vittoria C 2009 J. Magn. Magn. Mater. 321 2035
[4]	Novák P, Rusz J 2005 Phys. Rev. B 71 184433
[5]	Fang C M, Kools F, Metselaar R, With G and Groot R A 2003 J. Phys. C 15 6229
[6]	Knížek K, Novák P, Küpferling M 2006 Phys. Rev. B 73 153103
[7]	Braun P B 1957 Philips. Res. Rep. 12 491
[8]	Gorter E W 1957 Proc. IEE 104 B (suppl.) 255
[9]	Kresse G, Furthmüller J 1996 Phys. Rev. B 54 11169
[10]	Perdew J P, Burke K, Ernzerhof M 1996 Phys. Rev. Lett. 77 3865
[11]	Dudarev S L, Botton G A, Savrasov S Y, Humphreys C J, Sutton A P 1998 Phys. Rev. B 57 1505
[12]	Ŝimŝa Z, Zalesskij, Závěta K 1966 Phys. Stat. Sol. 14 485
[13]	Mattsson A E, Armiento R, Schultz P A, Mattsson T R 2006 Phys. Rev. B 73 195123; Paier J, Marsman M 2006 J. Chem. Phys. 124 154709
[14]	Collomb A, Wolfers P, Obradors X 1986 J. Magn. Magn.Mater. 62 57
[15]	Zhou F, Ceder G 2010 Phys. Rev. B 81 205113