Effect of the sintering temperature on microstructure and optical properties of reactive sintered YAG:Sm3+ ceramics

YAG:Sm3+ (5 аt.%) optical ceramics were obtained by the solid-state reactive sintering in the 1700–1800°C temperature range. The effect of the sintering temperature on the microstructure, phase composition and optical properties of YAG:Sm3+ ceramics has been studied. It has been shown that the optimal sintering temperature in order to produce YAG:Sm3+ transparent ceramics is 1725°С. The sintered ceramics are characterized by high optical transmittance (>82% at 808 nm), low residual porosity and the average grain size of 21 μm. It has been shown that the sintering temperature has a little effect on the average grain size of synthesized ceramics. Microstructure of YAG:Sm3+ ceramics consolidated at 1800°C is characterized by the presence of large grains up to 90 μm surrounded by the main fraction with an average grain size of 19 μm, which could be evidence of starting bimodal grain size distribution.