Thermal Conductivities of LaPO<sub>4</sub>/Al<sub>2</sub>O<sub>3</sub> Composites Fabricated by SPS

The thermal conductivities of the LaPO4/Al2O3 composites that were fabricated by spark plasma sintering (SPS) were determined. The results revealed that their thermal conductivities displayed nearly a slow decrease with increasing temperature from 25oC to 800oC, having the classic 1/T dependence. In addition, the conductivities of the composites decrease monotonously with increasing the LaPO4 content because of the lower thermal conductivity of LaPO4. The calculated conductivities of the composites using Maxwell equation match well the experimental values at both the end members of LaPO4 and Al2O3 being the continuous phase, but showing a little deviation at intermediate composition.