Spectra energy levels and symmetry assignments of Sm3+ doped in YAl3(BO3)4 single crystal

Single crystals of YAl3(BO3)4 doped with 5% Sm3+ were grown by spontaneous nucleation from K2Mo3O10 and B2O3 flux. Photoluminescence spectra at room and low temperatures were measured. Four emission transitions have been observed from the 4G5/2 excited state to the lower lying states 6H5/2, 6H7/2, 6H9/2 and 6H11/2 upon exciting the sample with 400 nm wavelength. Polarized absorption spectra in UV, visible and NIR regions were recorded for two light polarizations (π and σ) relative to the C3 crystal axis. Energy levels scheme of the doping ion has been compiled after a careful analysis of the spectra by reproducing the observed transitions by means of theoretical calculations based on a Hamiltonian including the free-ion and the crystal-field (CF) terms. Free-ion and crystal-field analyses are performed based on a D3 point-group symmetry Hamiltonian. A best fit between theoretical and experimental energy levels is obtained with a root-mean-square (rms) deviation of 16 cm−1. The general trend of the crystal-field parameters of rare earth ions in YAB host is confirmed. The calculated NV crystal-field strength parameter presents a linear variation with the rare earth ionic radii and with the 4fn electron number.