Fabrication of Nd:YAG transparent ceramics using powders synthesized by citrate sol-gel method

Abstract

Abstract The highly transparent Nd:YAG ceramics were prepared by using powders synthesized by citrate sol-gel method. The citrate sol-gel method could avoid defects of the solid-phase reaction method and the liquid phase co-precipitation method in preparing Nd:YAG ceramic powders with the ratio of (Nd3+, Y3+):Al3+ equal to 3:5. The dried gel was the three dimensional net-shaped porous structure. When the dried gel was calcined at 500\u202f°C in oxygen, pure YAG phase formed directly with no intermediate phases. The Nd:YAG powders calcined at 800\u202f°C had maximum particle size near 500\u202fnm. These powders were not equiaxed and there were dumbbell-like and annular grains. The highly compact Nd:YAG ceramics could be well sintered at 1750\u202f°C for 12\u202fh in vacuum atmosphere, and these sample had the average grain size about 3.8\u202fμm. The polished Nd:YAG ceramics was highly transparent, and the transmittances at 1064\u202fnm and 400\u202fnm were 83.4% and 74.2%, respectively. The fluorescence emission spectrum implied high possibility of realizing laser output at 1064\u202fnm by pumping at 808\u202fnm. Generally, the citrate sol-gel method was also a reliable choice for preparing high quality Nd:YAG transparent ceramics.