Spectroscopic and crystal-field analysis of energy levels of Eu3+ in SnO2 in comparison with ZrO2 and TiO2

Abstract

We have carried out systematic crystal-field energy level calculations of Eu3+ ions doped in SnO2 based on experimentally acquired luminescence spectra. In addition, with an aim of revealing systematic trends in spectra and crystal-field effects for Eu3+ ion in similar hosts, we have analyzed the TiO2 (anatase):Eu3+ spectra as well. The obtained crystal-field parameters yield very good agreement between the calculated and observed energy levels. Emphasis has been put on analysis of the crystal-field-induced J-mixing effects and their roles in getting proper sets of crystal-field parameters and energy levels. A more general theory concerning J-mixing effects has been proposed and the relevant results will be valuable to understanding of the spectral characteristics of Eu3+ f–f transition spectra in other hosts. Relations between the maximum crystal-field splitting of some selected J-manifolds with J=1 and J=2 and crystal-field invariants have been re-visited and re-derived. The corresponding numbers of crystal-field parameters influencing the splitting of these manifolds have been taken into account in every case. The derived equations have been tested in applications to three systems (SnO2, TiO2 (three sites) and ZrO2). Consistent results have been obtained, which confirms validity of the performed crystal-field analysis and opens a way for possible applications of the suggested calculating technique to other rare-earth ions.