The ionic spin-state, magnetic and electronic structures of double perovskite Pb2CoTeO6:An ab initio study

Abstract The Co-containing double perovskites are of considerable attention due to their intriguing physical properties. Herein, the magnetic coupling and electronic structures of ordered double perovskite Pb2CoTeO6 have been investigated based on the low-temperature P21/n phase using the first-principles calculations. It is foundthat Pb2CoTeO6 is an antiferromagnet with B-site Co antiferromagnetic coupling, and B′-site Te is nonmagnetic and does not contribute to the cell magnetic moment. Electronic structure analyses reveal the semiconducting nature of the compound with the electronic distribution of Pb2+2Co2+Te6+O2-6. In particular, the 3dxz and 3dyz orbitals of Co are exactly overlapped and behave as a single level 3dxz + yz, suggesting that Co2+ with 3 d7 electronic configuration and it splits into t2g and eg orbitals (t2g5eg2) in the high-spin state. Our study provides an alternative way for the straightforward understanding of the electronic distribution of Co and its inextricable effects on magnetism and electronic transport of the compounds.