Fabrication of transparent Y2Hf2O7 ceramics via vacuum sintering

Y2Hf2O7 transparent ceramics were successfully fabricated via vacuum sintering at 1900 °C for 6–12 h by the solid-state reaction using the corresponding nitrate and oxide powders without additives. The fabricated transparent ceramics showed a well-defined microstructure and no pores or other defects were observed. The linear optical transmittance reached to 60% in the visible wavelength region, which is about 76% of the corresponding single crystal. The refractive index of the Y2Hf2O7 transparent ceramics was above 2.01 in the region between 400 nm and 800 nm.

► Y2Hf2O7 powder was synthesized by the solid-state reaction method without additives.
► Y2Hf2O7 transparent ceramics were fabricated via vacuum sintering.
► The linear light transmittance reached 60% in the visible wavelength region.
► The refractive index transparent ceramics was above 2.01 from 400 nm to 800 nm.