Fabrication of transparent La-doped Y2O3 ceramics using different La2O3 precursors

Despite being the most common sintering additive of transparent Y2O3 ceramics, La2O3 still suffers from weight changes when used in manufacturing processes due to its absorption of moisture and carbon dioxide. In the present work, two stable precursors, La(OH)3 and La2O2CO3, were proposed for use as sintering additives for transparent Y2O3 ceramics; La2O3 powder was used for comparison. A series of experiments were conducted to investigate the influences of La2O3, La(OH)3 and La2O2CO3 on the optical properties of Y2O3 ceramics by comparing the properties of mixed powders, green bodies and their sintering behaviors. Samples using La(OH)3 or La2O2CO3 as sintering additives exhibited more favorable optical properties at similar sintering temperatures compared to those using La2O3. Transmittances close to the theoretical value at 4 μm were achieved for samples doped with La(OH)3 or La2O2CO3 sintered at 1800 °C.