Effects of Sintering on the Thermal and Optical Properties of Zinc Oxide Ceramic

Microstructure and composition are factors determining heat transfer in ZnO ceramic materials, which define the performance of the material after Joule heating, generated by electron transport. In this study, photothermal radiometry was applied to investigate the influence of the sintering temperature, ranging from 800 ^∘C to 1300 ^∘C , by measuring the thermal diffusivity and thermal conductivity at room temperature, of commercial and sol–gel ZnO pellets. Our results show that the values of these thermal properties for both types of ZnO increase when the sintering temperature increases, displaying maximum energy dissipation at 1200 ^∘C . Additionally, the role of the sintering temperature on the optical properties was also analyzed using diffuse reflectance spectroscopy, and from these data the optical band-gap was obtained.