Fabrication and characterization of highly transparent ZrO2-doped Tm2O3 ceramics

Highly transparent polycrystalline Tm 2 O 3 ceramics were successfully fabricated by vacuum sintering at temperatures from 1650 to 1850 °C for 8 h using commercial Tm 2 O 3 and ZrO 2 (1 at%) powders as starting materials. It is the first time that ZrO 2 was reported as a sintering additive to prepare Tm 2 O 3 transparent ceramics. The effects of sintering temperature on the optical transmittance and microstructure of Tm 2 O 3 transparent ceramics were studied. The desired Tm 2 O 3 ceramics with relative density of 99.8% and an average grain size of approximately 9.7 μm were obtained at 1800 °C and the in-line transmittance reached 75% at 880 nm and fluctuated around 80% from 2100 to 2400 nm, respectively. This study demonstrated that Tm 2 O 3 transparent ceramics with higher in-line transmittance and smaller grain size could be prepared by using ZrO 2 as sintering additive at a relatively lower vacuum sintering temperature compared to those already reported in open literatures.