摘要
基于密度泛函理论的广义梯度近似(GGA)和投影缀加波(PAW)方法,分别从共线和非共线磁性结构出发,研究了自旋阻挫三角反铁磁AgCrO2的基态、磁性以及电子结构,从理论计算的角度给出了基态磁性结构.计算结果表明:AgCrO2具有120°螺旋自旋序反铁磁基态,其自旋螺旋面平行于(110)面或(110)面;由于Cr离子间的自旋几何阻挫,导致沿晶体的a,b和a+b方向上均形成了螺旋自旋转动角为120°的相互平行的螺旋自旋链;对非共线磁性电子结构分析发现自旋阻挫效应使得Cr-3d态局域性增强,体系中Cr-Cr磁性相互作用变大,而自旋轨道耦合作用对电子结构影响微弱.
Based on the collinear and non-collinear magnetic structures,the ground state,magnetism and electronic structure of the frustrated triangular antiferromagnet AgCrO2 have been investigated using the density functional theory （DFT） within the generalized gradient approximation （GGA） with the projected augmented wave （PAW） method. Detailed magnetic structure has been elucidated vividly from the theoretical view. The calculations show that AgCrO2 magnetic ground state has 120° helical-spin order with its spiral plane parallel to the （110） or （110） plane. Due to the strong intra- and interlayer geometric spin frustration,parallel helical-spin chains arise along the a,b or a ＋ b direction with the screwrotation angle 120°. From the non-collinear electronic structure calculation,it is found that due to the spin frustration Cr3d orbital states near the Fermi level become more localized, indicating an enhanced interaction between Cr-Cr. Nevertheless,the spin-orbit coupling has weak influence on the electron structure.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第9期6487-6493,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:10874021)
扬州大学自然科学基金(批准号:GK0513102)资助的课题~~
关键词
第一性原理
交换相互作用
阻挫
反铁磁
first-principles
exchange interaction
frustration
antiferromagnet
