Electronic structure and magnetism of EuX (X = O, S, Se and Te): A first-principles investigation

¹  Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park - Hangzhou 310018, China
²  State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences - Shanghai 200050, China
³  Department of electronics, Jiangxi University of Finance and Economy - Nanchang 330013, China

Corresponding author: siqishi@yahoo.com

Received: 1 May 2008
Accepted: 24 July 2008

Abstract

Electronic structures and magnetic properties of EuX (X = O, S, Se and Te) are investigated by the plane-wave pseudopotential method with explicit account for Coulomb repulsion within the shell, and compared with other theoretical and experimental results. All the EuX compounds are magnetic semiconductors with noticeable indirect -X gap. Ferromagnetic ordering is observed for EuO and EuS while antiferromagnetic ordering along [111] is the ground state for EuSe and EuTe. These results are consistent with the experiments, although previous calculations indicated that the ground state of EuS is antiferromagnetic. The exchange parameters are calculated, and are in fair agreement with experimental results.