Observation of cross-ionization is Gd 3Sc 2Al 3O 12 : Ce 3+

Abstract

A cross-relaxation process has been observed in Gd 3Sc 2Al 3O 12 : Ce 3+ between Gd 3+ and Ce 3+ ions that results in a promotion of Ce 3+ electrons into the host conduction band. Energy transfer between the Gd 3+ and Ce 3+ ions is evident in the Ce 3+ excitation spectrum, which shows sharp features coinciding with Gd 3+ transition, in addition to the broad Ce 3+ 5d bands. To demonstrate the presence of a “cross-ionization” process we conducted photoconductive studies of the garnet. Photoconductivity is a direct way to detect electron transfer processes—in our case photoconductive studies confirm the promotion of an impurity electron into the host conduction band via energy transfer.