Theoretical study of the density of states and magnetic properties of electron-doped Sr1-xCexCoO3 compounds

摘要

Within the unrestricted Hartree-Fock approximation and the real space recursion method, we calculated the electronic structure of the Sr1-xCexCoO3 in the whole doping range 0.0 <= x <= 1.0. Various spin states in an enlarged double cell are investigated and five of them are the ground states at different doping concentration. The magnetic ground state of the doped system takes an intermediate-spin state for x < 0.02, a low-spin-intermediate-spin ferromagnetically ordered state for 0.02,<= x <= 0.38, and a low-spin-high-spin ferromagnetically ordered state for 0.38 <= x <= 0.79. For 0.79 <= x <= 0.9, the ground state of the system is the intermediate-spin chain-type anti-ferromagnetically ordered state, which is followed by the intermediate-spin nearest neighbor anti-ferromagnetically ordered state up to x = 1.0. The densities of states of all magnetic ground states are computed and their electronic and magnetic properties are discussed. (c) 2007 Elsevier B.V. All rights reserved.