COMPARATIVE CORRELATION CRYSTAL-FIELD ANALYSIS OF ER3+ (4F11) IN GARNET HOSTS

Comparative correlation crystal field (CCF) analyses of the Er3+ (4f11 ) energy level structure in YAG, LuAG, ErAG, ErGG, YSAG and YSGG syste ms are reported. These analyses are based on the use of a phenomenolog ical Hamiltonian model that includes 20 free-ion parameters and the ni ne one-electron crystal field parameters plus one two-particle CCF par ameter. The present analyses are carried out with a uniform Hamiltonia n model and common crystal field levels spanning the lowest 12 multipl ets. Comparison between the observed and calculated crystal field leve ls 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 a b initio calculations of CCF effects and also with the results of CCF of the Nd3+ ion.