Spectroscopic studies and dynamics of Nd3+ ions in RbY2Cl7 single crystals. Part I. Analysis of site-selective excitation and emission spectra Original Research Article

Single crystals of Nd3+:RbY2Cl7 were grown by the Bridgman–Stockbarger method. The host crystal contains two slightly inequivalent Y3+ ions, each with an approximate C2v site symmetry. The crystal-field energy levels of the Nd3+ 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 Nd3+ ions were proposed as explanatory for the results of the present investigations.