Co-precipitation synthesis and sintering of 4.5 at.% Sm:YAG nano-powders for cladding ceramics

High quality and fine grained 4.5 at.% Sm:YAG transparent ceramics were fabricated by vacuum pre-sintering and hot isostatic pressing (HIP) from the co-precipitated nano-powders. After component optimization, the Sm 0.135 Y 2.865(1+x) Al 5 O 12 (x = 0.005) transparent ceramics have the highest in-line transmittance. Alumina secondary phase was observed in the Sm 0.135 Y 2.865(1+x) Al 5 O 12 (x = −0.001, 0) ceramics. The Sm 0.135 Y 2.865(1+x) Al 5 O 12 (x = 0.001, 0.003, 0.005, 0.007) ceramics showed clear microstructures because of the yttrium ions anti-site defects (Y 3+ in Al 3+ positions) forming. By optimizing the pre-sintering temperature to 1450 °C, the 4.5 at.% Sm:YAG transparent ceramics with the thickness of 2.0 mm achieved a high in-line transmittance of 84.1 % at 808 nm after HIP post-treatment at 1550 °C for 3 h. Fine grain size of 730 nm and appropriate absorption coefficient of 2.94 cm −1  at 1064 nm were also achieved. It is indicated that the 4.5 at.% Sm:YAG transparent ceramics could effectively suppress amplified spontaneous emission and parasitic oscillation as a cladding layer of the high power Nd:YAG ceramic lasers. The co-precipitation method for synthesizing 4.5 at.% Sm:YAG nano-powders were reported in detail, and fine-grained transparent ceramics were fabricated.