Structural analysis and crystal-field calculations of Nd3+ in GdxLu1−xTaO4 (x = 0.85) polycrystalline

Abstract

The crystal structural parameters of Nd3+-doped rare earth orthotantalate GdxLu1−xTaO4 (x = 0.85) are determined by applying the Rietveld refinement to its X-ray diffraction, and its emission and excitation spectra at 77 K are analysed. The relativistic model of ab initio self-consistent DV-Xα method, which is applied to the cluster NdO8 in GdxLu1−xTaO4, and the effective Hamiltonian model are used to investigate its spin—orbit and crystal-field parameters. The free-ions and crystal-field parameters are fitted to the experimental energy levels at 77 K with a root-mean-square deviation of 14.92 cm−1. According to the crystal-field calculations, 96 levels of Nd3+ are assigned. Finally, the fitting results of free-ions and crystal-field parameters are compared with those already reported for Nd3+:YAlO3. The results indicate that the free-ion parameters are similar to those of the Nd3+ in GdxLu1−xTaO4 and YAlO3 hosts, and the crystal-field interaction of Nd3+ in GdxLu1−xTaO4 is stronger than that in YAlO3.