Spectroscopic studies and dynamics of Nd 3+ ions in RbY 2Cl 7 single crystals. Part I. Analysis of site-selective excitation and emission spectra

Abstract

Single crystals of Nd 3+:RbY 2Cl 7 were grown by the Bridgman–Stockbarger method. The host crystal contains two slightly inequivalent Y 3+ ions, each with an approximate C 2v site symmetry. The crystal-field energy levels of the Nd 3+ ion doped in the two slightly inequivalent sites of the host crystal have been measured by optical absorption spectroscopy as well as by laser-selective excitation and emission experiments. As many as 151 and 156 energy levels have been ascribed to the Nd(1) and Nd(2) sites, respectively. Emission transients of a number of the levels were determined. Strong fluorescence and upconversion transitions were recorded and some mechanisms involving excited state absorption and energy transfer between Nd 3+ ions were proposed as explanatory for the results of the present investigations.