Electronic, magnetic, optical and thermoelectric properties of CaCrNiOsO double perovskites

• Published in: RSC advances 2020-04, Vol.1 (27), p.16179-16186
• Main Authors: Bhandari, Shalika R, Yadav, D. K, Belbase, B. P, Zeeshan, M, Sadhukhan, B, Rai, D. P, Thapa, R. K, Kaphle, G. C, Ghimire, Madhav Prasad
• Format: Article
• Language: English
• ISSN: 2046-2069
• DOI: 10.1039/c9ra10775d

With the help of density functional theory calculations, we explored the recently synthesized double perovskite material Ca 2 CrOsO 6 and found it to be a ferrimagnetic insulator with a band gap of ∼0.6 eV. Its effective magnetic moment is found to be ∼0.23 μ B per unit cell. The proposed behavior arises from the cooperative effect of spin-orbit coupling and Coulomb correlation of Cr-3d and Os-5d electrons along with the crystal field. Within the ferrimagnetic configuration, doping with 50% Ni in the Cr-sites resulted in a half-metallic state with a total moment of nearly zero, a characteristic of spintronic materials. Meanwhile, the optical study reveals that both 1 xx and 1 zz decrease first and then increase rapidly with increasing photon energy up to 1.055 eV. We also found optical anisotropy up to ∼14 eV, where the material becomes almost optically isotropic. This material has a plateau like region in the σ xx and σ zz parts of the optical conductivity due to a strong 3d-5d interband transition between Cr and Os. In addition, we performed thermoelectric calculations whose results predict that the material might not be good as a thermoelectric device due to its small power factor. With the help of density functional theory calculations, we explored the recently synthesized double perovskite material Ca 2 CrOsO 6 and found it to be a ferrimagnetic insulator with a band gap of ∼0.6 eV.