铁磁态Co基层状氧化物Ca2Co2O5电子状态的研究  

Study on Electronic States of Ferromagnetic Co-based Layered Ca_2Co_2O_5 Oxide

作　　者：张飞鹏 杜玲枝 李辉 王朝勇 祁林 张坤书 田中敏 张久兴[3] 郝五零[4] ZHANG Fei-peng;DU Ling-zhi;LI Hui;WANG Chao-yong;QI Lin;ZHANG Kun-shu;TIAN Zhong-min;ZHANG Jiu-xing;HAO Wu-ling(Henan Provincial Engineering Laboratory of Building-Photovoltaics,Institute of Sciences, Henan University of Urban Construction,Pingdingshan 467036,China;School of Materials Sciences and Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Anhui Provincial Key Laboratory of Advanced Functional Materials and Devices,College of Materials Science and Engineering, Hefei University of Technology,Hefei 230009,China;School of Mathematics,Yunnan Normal University,Kunming 650500,China)

机构地区：[1]河南城建学院数理学院,建筑光伏一体化技术河南省工程实验室,平顶山467036 [2]石家庄铁道大学材料科学与工程学院,石家庄050043 [3]合肥工业大学材料科学与工程学院,新型功能材料与器件安徽省重点实验室,合肥230009 [4]云南师范大学数学学院,昆明650500

出　　处：《人工晶体学报》2018年第11期2322-2328,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(51572066,11402225);河南省自然科学基金面上项目(162300410007);河南省科技计划项目(132300410071);云南省应用基础研究计划项目(2016FB012)。

摘　　要：采用平面波超软赝势法研究了低自旋状态Co基典型层状氧化物Ca_2Co_2O_5的电子结构。结果表明,层状Co基氧化物Ca_2Co_2O_5呈金属型能带结构,具有明显的各向异性,能带中含有5个子能带,其中费米能附近的能带数量较多,呈较宽的带状分布。自旋向上的电子形成半导体型能带,带隙宽度为0. 37 e V,自旋向下的电子形成金属型能带。系统内部的电子对态密度贡献程度依s,p,d依次增大。Ca的电子形成的态密度对费米能附近的值贡献非常小,Co的d态电子对两层态密度贡献较大,其对系统电性能起着重要作用,且系统Co-O之间存在着较强的相互作用。Ca-Co-O层中的各态电子对态密度的贡献大于Co-O层中的各态电子对态密度的贡献。The electronic states of the ferroelectric representing Ca 2Co 2O 5 layered oxide was studied by the plane wave as well as the pseodopotential method.The results show that the Ca 2Co 2O 5 layered oxide has metallic type band structure with five sub-bands;the band structure is anisotropic with more bands near Fermi level,and the bands near Fermi level exhibits belt-like distribution.The band structure of the spin up electrons is semiconductor type with indirect band gap of 0.37 eV,however the band structure of the spin down electrons is metallic.The d state electrons contribute to density of states most,the p state electrons contribute to density of state less and the s state electrons contribute to density of state the least.The electrons of Ca contribute to density of state near Fermi level the least.The d state electrons of Co contribute to density of states very much within the two sub-layers,it is important for the system electric properties.There are strong interactions between Co and O within the system.The Ca-Co-O layer contributes to the system density of state more than that of the Co-O layer.

关 键 词：层状氧化物 铁磁态 电子结构 

分 类 号：TN37[电子电信—物理电子学] O646[理学—物理化学]