Studies of the spin-Hamiltonian parameters and the defect structure for Cu2+ at the rhombic Be2+ site of beryl crystal

摘要

The spin-Hamiltonian (SH) parameters (g factors g(i) and hyperfine structure constants A(i), where i = x, y, z) for Cu2+ at the rhombic Be2+ site of beryl (Be3Al2Si6O18) crystals are calculated from both the perturbation theory method (PTM) and the complete diagonalization (of energy matrix) method (CDM). The two methods are based on the cluster approach and so both the contribution to the SH parameters from the spin-orbit coupling parameters of central d(n) ion and that of ligand ion are included. The calculated results from the two theoretical methods are in reasonable agreement with the experimental values, suggesting that both methods are effective for the studies of SH parameters of 3d(9) ion in rhombic symmetry. The defect structural data (which are unlike the corresponding data in the host beryl crystal) of the rhombic Cu2+ center in beryl are also acquired from the calculations. The results are discussed.