Influence of TiO 2 doping on thermo-optical properties of pyrochlore Sm 2 (Zr 1–x Ti x ) 2 O 7 (0≤ x ≤0.15) ceramics

Abstract Sm 2 (Zr 1– x Ti x ) 2 O 7 (0≤ x ≤0.15) ceramics have been fabricated by pressureless-sintering method at 1973 K for 10 h in air. The influence of TiO 2 doping on microstructure and thermo-optical properties of Sm 2 (Zr 1– x Ti x ) 2 O 7 ceramics is investigated by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy measurements. The partial substitution of Ti 4+ for Zr 4+ results in a significant increase in emissivity at low wavelengths contrasted with undoped Sm 2 Zr 2 O 7 . Sm 2 (Zr 0.85 Ti 0.15 ) 2 O 7 ceramic exhibits a high emissivity of above 0.70 at 1073 K in a wavelength range of 3–16 µm, where the highest value at this temperature is more than 0.90 especially in the wavelength range of 9–14 µm. FT-IR spectra and optical absorption spectra unveil the mechanisms of enhanced emissivity in Sm 2 (Zr 1– x Ti x ) 2 O 7 (0.05≤ x ≤0.15) ceramics in the intermediate infrared range, especially at the wavelengths of 3–8 µm, due to Ti 4+ ion substitution for Zr 4+ ion.