A study on sintered TiO2 and TiO2/SiC composites synthesized through chemical reaction based solution method

Abstract

TiO2 and TiO2/SiC composites are synthesized through chemical route followed by solid-state sintering at 1450℃. The X-ray diffraction pattern shows the peaks of TiO2 and SiC for the compositional ratio up to 60:40 whereas no peak corresponding to TiO2 has been observed for the SiC percentage of 50 and 60. It is confirmed from the micro-Raman and Fourier transform infrared spectra that TiO2 has got diffused into the SiC surfaces and interfaces in the composites having higher percentages of SiC. Maximum hardness has been observed for the TiO2 and SiC composition of 50:50. No optical transition has been observed for the composites with TiO2: SiC ratio equal to or below 1.5. The increase in absorption percentages with increasing concentration of SiC indicates that these composites can be utilized as photo-catalytic active material in visible light. The electrical resistivity measurements clearly show the increase in conductivity with increase in SiC percentage up to 50% in TiO2/SiC composites. All these TiO2/SiC composites are found to have carrier concentration in the order of 1016–1018/cm3 at room temperature and hence can be proven as good ceramic semiconductors. It is observed that the insulating nature of TiO2 gets transformed to the semiconducting nature by the addition of SiC. The electrical, mechanical and optical properties are also found to be strongly dependent on the SiC percentages.