Theoretical calculations of g factors for the tetragonal Ce3+ centers in AWO4 (A=Ca, Sr, Pb) and A′MoO4 (A′=Sr, Pb) crystals

The EPR g factors g// and g⊥ for the tetragonal Ce3+ centers in AWO4 (A=Ca, Sr, Pb) and A′MoO4 (A′=Sr, Pb) crystals with scheelite-type structure are calculated in terms of the complete diagonalization (of energy matrix) method. In the matrix, the crystal field parameters Bkq are estimated from the superposition model where the intrinsic parameters A¯k(R0) are taken as those obtained in very similar (CeO8)13− clusters in MPO4 (M=Y, Lu) crystals. The calculated g-values are in reasonable agreement with the experimental data when both covalence of the rare earth ion clusters, reflected in the presence of an orbit reduction factor k<1, and the local deformation due to the difference between the Ce3+ and host lattice cation radii are considered.