Calculations of the optical and EPR spectral data for Cr³⁺ion in Y₃Ga₅O₁₂crystal from the complete diagonalisation method

Abstract

2015) Calculations of the optical and EPRspectral data for Cr 3+ ion in Y 3 Ga 5 O 12 crystal from the complete diagonalisation method,The complete diagonalisation (of energy matrix) method is applied in this paper to calculate together the optical and electron paramagnetic resonance (EPR) spectral data for Cr 3 + ion at the trigonal Ga 3 + site of Y 3 Ga 5 O 12 crystal. The method is founded on the two-spin-orbit-parameter model where in addition to the contributions from the spin-orbit parameter of central d n ion (i.e., one-spin-orbit-parameter model) in the traditional crystal field theory, those from the spin-orbit parameter of ligand ion via covalence effect is also considered. The calculated results propose that by using only four adjustable parameters, the 12 observed spectral data (nine optical band positions and three EPR parameters g // , g ⊥ and D) in Y 3 Ga 5 O 12 : Cr 3 + are reasonably explained. The impurity-induced local lattice distortion of Cr 3 + in Y 3 Ga 5 O 12 crystal is also estimated through the calculations. The results are discussed.