First principle study of the magnetism of Sr2CoMoO6-delta (delta=0, 1/2) double perovskites

摘要

We investigate the electronic structure of bulk Sr2CoMoO6-delta double perovskites using the ab initio Full Potential Linearized Augmented Plane Wave method in order to study their magnetic properties within the GGA and GGA+U methods. We discuss the relative stability of ferromagnetic (FM) and antiferromagnetic (AFM) orders (i) without and with taking into account the observed tilting of the oxygen octahedra and (ii) by introducing oxygen vacancies. We show that a very good agreement with experimental results - AFM order for delta= 0 and FM order for delta= 1/2 - is obtained only when the tilting of the oxygen tetrahedra is taking into account and when the GGA+U method is used.