Study on the spin-states of cobalt-based double-layer perovskite Sr2Y0.5Ca0.5Co2O7
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210093, P.R. China
Corresponding author: a firstname.lastname@example.org
Revised: 22 January 2008
Published online: 7 March 2008
The spin-states of cobalt based perovskite compounds depend sensitively on the valence state and local crystal environment of Co ions and the rich physical properties arise from strong coupling among charge, spin, and orbital degrees of freedom. While extensive studies have been carried out in the past, most of them concentrated on the isotropic compound LaCoO3. In this paper, using the unrestricted Hartree-Fock approximation and the real-space recursion method, we have investigated the competition of various magnetically ordered spin-states of anisotropic double-layered perovskite Sr2Y0.5Ca0.5Co2O7. The energy comparison among these states shows that the nearest-neighbor high-spin-intermediate-spin ferromagnetically ordered state is the relevant magnetic ground state of the compound. The magnetic structure and sizes of magnetic moments are consistent with the recent experimental observation.
PACS: 75.25.+z – Spin arrangements in magnetically ordered materials / 71.20.-b – Electron density of states and band structure of crystalline solids / 71.30.+h – Metal-insulator transitions and other electronic transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008