Theoretical studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Gd(3+) center in cubic c-RbZnF(3) crystal

A diagonalization (of the energy matrix for which the Hamiltonian contains the free ion, crystal-field interaction and Zeeman interaction terms) method was applied to calculate the spin-Hamiltonian parameters (g factors, g // and , and five zero-field splittings, ) for the tetragonal Gd3+ center in cubic c-RbZnF3 perovskite. The calculated results are in reasonable agreement with experimental values. From the calculation, the defect model that the tetragonal Gd3+ center is attributed to Gd3+ occupying the 12-fold coordinated Rb+ site associated with a nearest Rb+ vacancy, VRb, along C 4 axis owing to charge compensation is confirmed and the defect structural data of this Gd3+ impurity center in c-RbZnF3 are acquired. The results are discussed.