SrTcO3晶体结构和电子结构的第一性原理研究

摘要

Density-functional theory with generalized gradient approximation is applied to the study of the crys-tal and electronic properties of SrTcO3. The crystal structure is found to be orthorhombically distorted perovskite structure with space group Pnma, and the electronic structure is found to be insulating and G type antiferromag-netic, in which each Tc moment is antiparallel to its six nearest neighbours. A high Neel temperature of 948 K is predicted with the mean-field approximation because of the strong Tc 4d-O p hybridization and the large spa-tial extent of the 4d shells.%利用基于密度泛函的第一性原理计算方法，对钙钛矿型氧化物SrTcO3的基态晶体结构、电子结构、磁性质和尼尔温度进行计算。计算结果表明：SrTcO3的基态空间群是Pnma，晶体中氧八面体中心离子Tc在三维方向上都呈自旋反平行排列，是G类反铁磁绝缘体。 Tct2g-Op强烈的轨道杂化和Tc4d电子的巡游特性共同作用，导致SrTcO3具有948K的高尼尔温度。