Yb:Sc₂O₃ Transparent Ceramics Fabricated from Co-precipitated Nano-powders: Microstructure and Optical Property

Sc 2 O 3 , as a host for solid-state laser gain materials, has advantage of high thermal conductivity and easy matching with activating ions, which is promising in high-power laser applications.Currently, Yb-doped Sc 2 O 3 ceramics have been fabricated at very high sintering temperatures, but their optical quality and sintering process still need further improvement.In this work, 5%Yb:Sc 2 O 3 (in mass) nano-powders were obtained by co-precipitation, and then transparent ceramics were fabricated by vacuum pre-sintering and hot isostatic pressing (HIP) post-treatment.The cubic Yb:Sc 2 O 3 nano-powders with good dispersity and an average crystallite of 29 nm were obtained.Influence of pre-sintering temperatures (1500-1700 ) on densification process, microstructure changes, and optical transmittance of Yb:Sc 2 O 3 ceramics was detected.Experimental data revealed that all samples have a uniform microstructure, while the average grain sizes increase with the increase of the sintering temperatures.Impressively, the optimum in-line transmittance of Yb:Sc 2 O 3 ceramics, pre-sintered at 1550 after HIP post-treatment, reaches 78.1% (theoretical value of 80%) at 1100 nm.Spectroscopic properties of the Yb:Sc 2 O 3 ceramics reveal that the minimum population inversion parameter 2 and the luminescence decay time of 5%Yb:Sc 2 O 3 ceramics are 0.041 and 0.49 ms, respectively, which demonstrate that the optical quality of the Yb:Sc 2 O 3 has been improved.Meanwhile, their best vacuum sintering temperature can be controlled down to a lower temperature (1550 ).In conclusion, Yb:Sc 2 O 3 nano-powders are successfully synthesized by co-precipitation method, and good optical quality transparent ceramics are fabricated by vacuum pre-sintering at 1550 and HIP post-treatment.