Theoretical Investigations on the Off-Center Displacement of Co2+ in SrO by Analyzing Its Anisotropic g Factors

Abstract

The off-center displacement of Co2+ ion in SrO crystal is investigated by analyzing its anisotropic g factors gx, gy and gz through diagonalization of the 6 × 6 energy matrix within 4T1 ground state for a 3d7 ion under rhombic symmetry. In the matrix, the contributions from the admixtures of various J( = 1/2, 3/2, 5/2) states and the fourth-order term Dη of rhombic crystal-fields and the ligand orbitals and spin-orbit coupling interactions, which are usually ignored in the previous studies, are considered. Both g factors (gx = 4.172, gy = 5.004 and gz = 2.133) and the off-displacement value (ΔR ≈ 0.023 nm) show good agreement with the experimental data.