Thermal properties of a prospective thermal barrier material: Yb3Al5O12

In this article, a comprehensive investigation on the thermal properties of Yb3Al5O12 is conducted, including Debye temperature, thermal expansion coefficient (TEC), thermal diffusivity, heat capacity, and thermal conductivity. The calculated Debye temperature of Yb3Al5O12 from the measured elastic properties is 625 K. The linear and volumetric thermal expansions of Yb3Al5O12 from 298 to 1273 K are (7.83 +/- 0.14) x 10(-6) and (23.74 +/- 0.42) x 10(-6) K-1, respectively. The linear TEC of the polycrystalline bulk Yb3Al5O12 determined by dilatometer is (8.22 +/- 0.3) x 10 (6) K (1). The measured thermal conductivities of Yb3Al5O12 are 4.67 and 2.05 W (m K)(-1), respectively, at 300 and 1400 K. The estimated minimum thermal conductivity, kappa(min), is 1.22 W (m K)(-1). The high temperature thermal conductivity is close to the evaluated kappa(min), which is lower than most commonly used thermal barrier coating (TBC) material such as Y2O3-stabilized-ZrO2 (YSZ). The unique combination of these properties renders Yb3Al5O12 being a very promising candidate material for TBC.