Yb3+ doped Lu2O3 transparent ceramics by spark plasma sintering

Transparent ceramics of 10% Yb doped Lu2O3 was fabricated by spark plasma sintering. The operating vital parameters in yielding transparency and mutual effects of sintering, pressure, dwell time, heating rate and annealing temperature on microstructure have been investigated. Fully compacted specimens were obtained at 1250 °C and the average grain size increased from few nm up to 5 μm until 1700 °C, above which abnormal grain growth was witnessed. The post-annealing of sintered ceramics at 1200 °C removes discoloration and improves transparency. The ceramics prepared at 1700 °C with dwell time of 5 min and heating rate at 50 °C/min shows the maximum transmittance with a thickness of 2 mm of 55% at a wavelength of 2 μm.