TiO2-assisted Mg-Ti-O-based ceramics improve thermal conductivity and microwave dielectric properties by modifying the microstructure

The influence of TiO2 on the crystal phase, microstructure, thermal conductivity, and microwave dielectric properties of Mg-Ti-O-based ceramics during sintering are explored. XRD analysis reveals that doped TiO2 completely reacts with Mg2TiO4 to generate MgTiO3, and (1-y)Mg2TiO4 + yMgTiO(3) ceramics are obtained. The undoped TiO2 samples exhibit an excessively large grain size with an uneven grain size distribution and numerous pores. The reaction between TiO2 and Mg2TiO4 effectively reduces the grain size of Mg2TiO4 to a reasonable range, thereby facilitating the mitigation of internal defects within grains. Additionally, the formation of MgTiO3 results in a microstructure characterized by two phases with staggered distribution and mutual inhibition. This phenomenon aids in controlling the growth and arrangement of grains, ultimately filling pores and enhancing ceramic density. A reasonable grain size and regular arrangement are advantageous for improving the thermal and dielectric performance of ceramics compared to excessively larger grains and uneven distribution. Mg-Ti-O-based ceramics contribute to an enhancement in thermal conductivity to 10.1 W/(m<middle dot>K) and in Qxf value to 143,046 GHz.