Crystal field study of Chromium(III) ions doped antimony phosphate glass: Fano’s antiresonnance and Neuhauser models

The absorption spectrum of antimony phosphate glass doped with Cr 3+ is characterized by the presence of features on the 4 T 2g ( 4 F) absorption band. These features result from the interaction of the 2 E g ( 2 G) and 2 T 1g ( 2 G) sharp levels with the vibrationally broadened 4 T 2g ( 4 F) quasi-continuum via spin-orbit coupling called interference dips. We have analyzed this phenomenon through two models: Fano’s antiresonance and Neuhauser models. This analysis permits us to determine the electronic structure of the chromium ion Cr 3+ based on the crystal field theory. As a result, Racah and crystal-field parameters have been reliably obtained. A good agreement between the theoretical and the experimental energy levels are obtained.