Abstract
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 (4)G(5/2) excited state to the lower lying states H-6(5/2), H-6(7/2), H-6(9/2) and H-6(11/2) upon exciting the sample with 400 nm wavelength. Polarized absorption spectra in UV, visible and NIR regions were recorded for two light polarizations (pi and sigma) relative to the C-3 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 D-3 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 N-v crystal-field strength parameter presents a linear variation with the rare earth ionic radii and with the 4f(n) electron number. (c) 2012 Elsevier B.V. All rights reserved.