High infrared transmission of Y3+–Yb3+-doped α-SiAlON

Dense dual Y3+–Yb3+-doped α-SiAlON ceramic containing extra addition of 2 wt.% Y2O3/Yb2O3 was fabricated by hot pressing at 1900 °C for 1 h, and its optical transmittance was investigated over the wavelength range 200–6000 nm. The results showed that the addition of 2 wt.% extra liquid phase could effectively promote Y/Yb-α-SiAlONs densification and its assemblage only consisted of single crystallized α-SiAlON phase. The obtained sample had relatively high infrared light transmittance properties. The maximum transmittance in the medium infrared region for 1.0 mm thick specimen could reach around 72% at ~ 2500 nm. It is attributed to the uniform, dense microstructure and few residual intergranular phases.