| Abstract Scope |
α-SiAlON ceramics were prepared by doping various rare earths. As a result, transparent ceramics with high α-SiAlON fraction was able to be fabricated by adding Ho, Er, Tm, Yb, and Lu oxides. Smaller ionic radii of rare earth ions result in the easier nucleation of α-SiAlON due to the wide α-SiAlON formation region, and the suppression of grain growth due to higher viscosity of liquid phase existing in the ceramics. Consequently, the microstructure composed of finer α-SiAlON grains is attributed to the high transparency. The obtained transparent α-SiAlON ceramics also exhibit luminescence due to Ho3+, Er3+, Tm3+, Yb3+, and Yb2+. Furthermore, by co-doping Lu3+ and Ce3+, α-SiAlON ceramics with high transparency and blue luminescence due to the 4f-5d transition of Ce3+ were also obtained. |