Effects of ball milling and post-annealing on the transparency of spark plasma sintered Lu2O3

The effects of ball milling of starting powder and post-annealing of spark plasma sintered (SPSed) Lu2O3 on its microstructure and optical property were investigated. When ball-milled powder was used, the SPSed Lu2O3 was found to have a larger grain size with wider distribution and lower transparency than in the case using powder without ball milling. After annealing at 1323 K in air, the Lu2O3 that was SPSed using ball-milled powder became colorless, had a higher transmittance in the visible spectrum than the case where as-received powder was used, and exhibited transmittances of 71.4% and 81.6% for wavelengths of 550 and 2000 nm, respectively.