Synthesis of Transparent Nd‐doped HfO 2 ‐Y 2 O 3 Ceramics Using HIP

A Nd‐doped HfO 2 ‐Y 2 O 3 ceramic having excellent transmittance was synthesized by HIPing, using high‐purity powders (>99.99 wt%) of Y 2 O 3 , Nd 2 O 3 , and HfO 2 . The mixed powder compacts of these powders were sintered at 1650°C for 1 h under vacuum and HIPed at 1700°C for 3 h under 196 MPa of Ar. The specimen after HIPing consisted of uniform grains measuring about 30 μm and having pore‐free structure. The optical transmittance of 1 at.% Nd‐doped 2.6 mol% HfO 2 ‐Y 2 O 3 ceramics ranging between visible and infrared wavelength was almost equivalent or superior to that of a Nd:Y 2 O 3 single crystal grown by the Verneuil method.