RCrO4(R=Er,Tm)的电子结构和半金属铁磁性

摘要

用第一性原理研究了RCrO4(R=Er和Tm)氧化物的电子能带结构和半金属铁磁性,发现锆石相的RCrO4是优质的半金属铁磁材料,具有达到0.35eV的半金属能隙.为了研究磁相互作用的机制,采用密度泛函理论和广义梯度近似计算电子能带结构、态密度和自发磁矩,发现其磁性来源于R的f轨道电子、Cr的d轨道电子和O的p轨道电子的自旋极化.穿过费米能级的能带主要来源于R(4f)-O(2p)-Cr(3d)的杂化能级,并对磁性和电子输运性质起着关键作用.%First-principles electronic calculations are used to study the electronic band structure and the half-metallic ferromagnetism of the RCrO4 (R=Er and Tm) oxides. The Zircon RCrO4 (R=Er and Tm) phases are found to be excellent half-metallic ferromagnets with large half-metallic gaps (up to0.35 eV). The calculations are based on density-functional theory with the generalized gradient approximation. In order to study the mechanism of magnetic interactions, the electronic band structure,the density of states and the spontaneous magnetic moment were calculated. It is found that magnetism comes from spin-polarization of electrons in f-orbits of R, d-orbits of Cr and p-orbits of O.The bands crossing the Fermi level, which are from the hybridized bands of R(4f)-O(2p)-Cr(3d),play an essential role in magnetic and transport properties.