Preparation and thermophysical properties of LaMgAl11O19–Yb3Al5O12 ceramic composites

LaMgAl11O19–Yb3Al5O12 ceramic composites were prepared by pressureless sintering process at 1700 °C for 10 h in air. The microstructure and thermophysical properties of the composites were characterized by X-ray diffraction, scanning electron microscopy, high-temperature dilatometer and laser flash diffusivity measurements. LaMgAl11O19–Yb3Al5O12 ceramic composites are composed of magnetoplumbite and garnet structures. LaMgAl11O19–Yb3Al5O12 ceramic composites exhibit typical linear increase in thermal expansion with the increase of temperature. The measured thermal diffusivity gradually decreases with increasing temperature. Thermal conductivity of LaMgAl11O19–Yb3Al5O12 ceramic composites is in the range of 2.6–3.9 W·m−1·K−1 from room temperature to 1200 °C.