Evaluation of the efficiency of Cr3+ → Cr4+ conversion in non-stoichiometric YAG: Cr ceramics

Abstract

The aim of the work was to study the effect of the YAG: Cr ceramics' stoichiometry deviation on the optical properties and efficiency of valence conversion of Cr cations. YAG: Cr ceramic powders with deviations from stoichiometry ranging from 0.225 to −0.35 at % excess yttrium were synthesized by chemical precipitation. The optical and luminescent properties of YAG: Cr4+ ceramics, as well as the microstructure of the ceramics, were studied. It has been shown that small deviations from the stoichiometry of YAG: Cr (within 0.35 at %) do not have a significant effect on the optical transmission and microstructure of YAG: Cr3+ ceramics, but strongly affect some characteristics of YAG: Cr4+ ceramics. It was found that the presence of excess aluminum or yttrium cations in YAG: Cr4+ ceramics leads to a decrease in the concentration of Cr4+ and a deterioration in the conversion from Cr3+ to Cr4+.