Influence of Phase Separation on Thermal Conductivity of Ti1-xSnxO2 Ceramics

Many technologically important ceramic materials are made of more than one component. If components are isostructural they can form a stable or a metastable solid solution that can undergo phase separation below a critical temperature, which can significantly affect different properties of the material. In this work, we investigated the effect of phase separation on thermal conductivity at room temperature of Ti1-xSnxO2 ceramic with different Ti/Sn ratios. The samples were sintered at 1500 degrees C and afterwards annealed at 1100 degrees C for 48 h in order to induce phase separation. It was observed that substitution of Ti with Sn and vice versa considerably reduces the thermal conductivity of the parent phases (TiO2 and SnO2). The thermal conductivity of the samples with compositions inside the spinodal region after annealing increased compared with that of samples that had not been annealed while for the compositions outside the spinodal region, only a limited effect was observed.