Synthesis and characteristics of transparent Gd ₂O ₃ ceramics with cubic structure

Transparent Gd₂O₃ ceramics with a cubic crystal structure have been successfully synthesized for the first time. Gd₂O₃ ceramics HIP-treated at 1070 °C consisted of uniform grains of 2~3 μm, and only a few residual pores could be detected inside the material. XRD diffraction shows that the obtained polycrystalline material has a cubic crystal structure, and transmission polarized light observation shows that there is no birefringence inside the material, indicating the inherent optical properties of the cubic crystal structure. The optical absorption edge is 640 nm (optical band gap: 2.1 eV), and the transmittance in the visible to near-infrared region is 72 %, which is close to the theoretical transmittance calculated from the Fresnel loss. The Verdet constant of this material is almost wavelength-independent, and it is diamagnetic since it has the opposite polarity to that of common paramagnetic materials.