Fabrication and characterization of transparent ceramics for solid state laser applications

Abstract

Solid state laser ceramics had caught the attention of researchers from around the world. This project serves to evaluate the effects of ammonium sulfate on the morphology of co-precipitated powders and how sintering temperature affect the transparency of yttrium oxide ceramics. Both factors are studied to reduce the porosity to attain transparent ceramic for solid-state laser application. A comparison between solid state reaction and wet chemical co-precipitation was done. Particles synthesized by co-precipitation show less agglomeration and narrow particle size distribution. It was proved that 50.at% ammonium sulfate was sufficient to obtain uniform particle size distribution with little agglomerations. The presence of ammonium sulfate resulted in good powder dispersity. Ceramics with 50.at% ammonium sulfate was sintered at 3 different temperatures, 1650ºC, 1750ºC and 1850ºC. At 1850ºC, yttrium oxide ceramic exhibited no pores with uniform grain size. In-line transmittance was measured for all 3 ceramics sintered at different temperature. After sintering at 1850 ºC, the Y2O3 ceramic exhibited the highest transmittance, which achieved 69% at 2000 nm. Y2O3 ceramic sintered at 1650 ºC, however, was translucent. To attain fully transparent Y2O3 ceramic, future improvement could be done on reducing its porosity further.