title: g factors and the tetragonal distortion of ligand octahedron for Co2 + in Rb2MgF4 crystal.
abstract: The calculation formulas of g-factors g(parallel) and g(perpendicular) for 3d7 ion in tetragonal octahedral crystals are established from a cluster approach. In these formulas, the parameters related to covalency effect, configuration interaction and low-symmetry crystal field can be determined from the optical spectra and the structural data of the studied system. Based on these formulas, the structural parameters of ligand octahedra of Co2+ in Rb2MgF4 crystal are obtained by fitting the calculated g(parallel) and g(perpendicular) to the observed values. The result suggests that the CoF6 (and hence MgF6) octahedra in Rb2MgF4:Co2+ are tetragonal compressed. The relationship between the sign of deltag( = g(perpendicular) - g(parallel)) and the sign of distortion (elongated or compressed) of ligand octahedron and the causes of the mistakes of octahedron distortion for Rb2MgF4:Co2+ in the previous papers are discussed.
authors.affiliation: Department of Material Science, Sichuan University, Chengdu, People's Republic of China. zhengwenchen@netease.com
authors.forename: Z
authors.initials: Z
authors.lastname: Wen-Chen
authors.forename: W
authors.initials: W
authors.lastname: Shao-Yi
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D003460:Crystallization; D003461:Crystallography; D004578:Electron Spin Resonance Spectroscopy; D005459:Fluorides / Q000737:chemistry*; D008962:Models, Theoretical; D012413:Rubidium / Q000737:chemistry*
chemical_list: C419879:rubidium magnesium chloride; D003035:Cobalt; D012413:Rubidium; D005459:Fluorides