Heating parameter optimization and optical properties of Nd:YAG transparent ceramics prepared by microwave sintering

摘要

Nd-doped YAG transparent ceramics were prepared by microwave sintering. In this paper, the green bodies from high-purity commercial powders were sintered from 900 degrees C to 1750 degrees C for different lengths of time (0.5-2 h) by microwave heating. By optimizing the microwave heating parameters (the heating rate at different stages of microwave sintering, sintering temperature and holding time), the microstructures and optical properties of transparent ceramics can be effectively improved. The phase transformation, densification process and optical properties of Nd:YAG transparent ceramics were discussed. The liquid phases strongly absorb microwave radiation and affect the sintering results of samples during microwave sintering. The highest in-line transmittances of Nd:YAG transparent ceramic fabricated at 1750 degrees C for 2 h were 76.5% at 400 nm and 80.6% at 1064 nm. The fluorescence emission spectra and lifetime depending on different heating conditions were also discussed.