Theoretical study of electron paramagnetic resonance spectra and local structure of trigonal [Cr(H_2O)_6]~(3+) complex in GASH:Cr~(3+)and AlCl_3.6H_2O:Cr~(3+) systems at different temperatures

摘要

The electron paramagnetic resonance (EPR) parameters and local structure of the octahedral [Cr(H_2O)_6]~(3+)complex for Cr~(3+) doped in GASH and AlCl_3 .6H_2O crystals with trigonal symmetry have been studied on the basis of the 120 x 120 complete energy matrices, respectively. By simulating the EPR and optical spectra, the local structure distortion parameters are determined in the temperature range of 4.2-297 K. The calculated results show that the local structure of [Cr(H_2O)_6]~(3+) octahedron exhibits an elongated distortion and the value of distortion depends on the temperature. Furthermore, the interrelation between the g-factors and orbit-reduction factor k has been studied, and the influence of the local structure on the EPR parameters has also been discussed.