Fabrication and luminescence properties of highly transparent and submicrometer-grained Yb:Y2O3 ceramics by hot-pressing sintering

Highly transparent and submicrometer-grained Yb:Y2O3 ceramics were obtained by hot-pressing method with ZrO2 sintering additive. Hot-pressing method provides extra driving force to promote the densification of Yb:Y2O3 transparent ceramics, resulting in high transmittance achieved. The transmittances of all samples were ranging from 80.5% to 81.8% at 1100 nm and 72.7–77.7% at 600 nm. The ceramic samples in this work were sintered at a low temperature of 1600 ℃ for 3 h, providing dense microstructures with average grain size less than 1 µm, which are smaller than those of Yb:Y2O3 ceramics prepared by other traditional sintering techniques. The microhardness and fracture toughness were ranging from 8.16 to 7.99 GPa, and from 0.94 to 0.88 MPa·m1/2, respectively, which are higher than the comparison samples fabricated by pressureless sintering. The absorption cross-sections of the 1 at% Yb-doped sample at 950 and 976 nm were 0.93 × 10−20 and 1.22 × 10−20 cm2, respectively. The fluorescence decay lifetime at 1032 nm was in the range of 0.79–1.36 ms. According to the available literature, this is the first report about Yb:Y2O3 transparent ceramics fabricated by hot-pressing sintering without any combined sintering process. The ceramics obtained may have potential use for solid-state lasers partly replacing single crystals.