Synthesis of transparent Nd-doped HfO2-Y2O3 ceramics using HIP

A Nd-doped HfO2-Y2O3 ceramic having excellent transmittance was synthesized by HIPing, using high-purity powders (>99.99 wt%) of Y2O3, Nd2O3, and HfO2. The mixed powder compacts of these powders were sintered at 1650 degrees C for 1 h under vacuum and HIPed at 1700 degrees C for 3 h under 196 MPa of Ar. The specimen after HIPing consisted of uniform grains measuring about 30 mu m and having pore-free structure. The optical transmittance of 1 at.% Nd-doped 2.6 mol% HfO2-Y2O3 ceramics ranging between visible and infrared wavelength was almost equivalent or superior to that of a Nd:Y2O3 single crystal grown by the Verneuil method.