Submicrometer Grain‐Sized Transparent Erbium‐Doped Scandia Ceramics

Erbium‐doped transparent Sc 2 O 3 ceramics with an average grain size of 0.3 μm were synthesized from solution‐derived nanoparticles using a two‐step sintering process followed by hot isostatic pressing (HIP). The two‐step sintered ceramics showed a remarkable decrease in grain size with relative density over 98% before HIP. After HIP, the Sc 2 O 3 ceramics became highly transparent, with negligible grain growth, and exhibited an optical transmittance of about 80%, nominally the Fresnel limit, for wavelengths greater than about 1.0 μm.