三角反铁磁AgCrO_2磁结构和磁电性质研究  

Investigation on the Magnetic Structure and Magneto-electric Properties of the Triangular Antiferromagnet AgCrO_2

作　　者：江学范[1] 刘先锋[2] 

机构地区：[1]常熟理工学院江苏省新型功能材料重点建设实验室,江苏常熟215500 [2]扬州大学物理科学与技术学院,江苏扬州225002

出　　处：《常熟理工学院学报》2009年第10期7-14,共8页Journal of Changshu Institute of Technology

基　　金：国家自然科学基金项目(10874021);江苏省高校自然科学基础研究项目(06KJA43014)

摘　　要：从多铁材料出发,介绍了三角反铁磁多铁材料ACrO2(A=Li,Na,K,Ag或Cu)的最新研究进展.这类多铁材料的磁性和铁电性存在很强的耦合和相互调控效应,铁电性来源于非共线螺旋自旋序,具有丰富的物理内涵,在自旋电子学等领域有着广阔的应用前景.基于密度泛函理论(DFT)的投影扩充波(PAW)方法,在广义梯度近似(GGA)下,对AgCrO2的磁结构和磁电性质进行了研究.共线磁结构计算结果表明,AgCrO2材料具有条纹反铁磁基态.态密度分析显示,Cr3+对体系的物理性质起决定性作用.通过非共线磁性结构计算,分别给出了平行于(110)而(110)面内120°自旋构型.AgCrO2与(110)具有很强的层内耦合作用,而层间耦合作用非常微弱,是典型二维三角格子Heisenberg材料.Beginning with the multiferroic material, recent advances in triangular antiferromagnets ACrO2 （A=Li, Na, K, Ag, or Cu） are introduced. The ferroelectricity of compounds ACrO2 is driven by spiral-spin ordering. Due to the combination of magnetic and dielectric properties, with eventual cross-coupling between these properties, such muhiferroics combine very rich and interesting fundamental physics problems with a technologically appealing po- tential for applications in the general area of spintronic. The magnetic structure, electronic structure and magnetism of AgCrO2 have been studied by using the density function theory （DFT） with the generalized gradient approximation （GGA） using the projected augmented wave （PAW） method. Based on the collinear magnetic structure calculation, the magnetic ground state is found to be striped antiferromagnetic. The density of states indicates that the physics properties of AgCrO2 are determined by Cr^3＋. By performing non-collinear magnetic structure calculations, the 120° spin structure within the spiral plane parallel to （110） or （11^0） plane are given, respectively. AgCrO2 is expected to be a good two-dimensional triangular lattice Heisenberg material with strong interlayer coupling and very weak interlayer interaction.

关 键 词：多铁性 三角反铁磁 螺旋自旋序 电子结构 磁交换作用 

分 类 号：O48[理学—固体物理]