Comparative correlation crystal field analysis of Er 3+ (4f 11) in garnet hosts

Abstract

Comparative correlation crystal field (CCF) analyses of the Er 3+ (4f 11) energy level structure in YAG, LuAG, ErAG, ErGG, YSAG and YSGG systems are reported. These analyses are based on the use of a phenomenological Hamiltonian model that includes 20 free-ion parameters and the nine one-electron crystal field parameters plus one two-particle CCF parameter. The present analyses are carried out with a uniform Hamiltonian model and common crystal field levels spanning the lowest 12 multiplets. Comparison between the observed and calculated crystal field levels yields good agreement with rms deviations between 7.7 cm −1 (Er:ErGG) and 11.5 cm −1 (Er:YAG). The fits are in qualitative agreement with ab initio calculations of CCF effects and also with the results of CCF of the Nd 3+ ion.