Preparation of ultralow thermal conductivity (Mg0.5Ca0.3Ba0.2) (AlSi)2O8ceramics

A type of nonequimolar multicomponent ceramic solid solution (Mg0.5Ca0.3Ba0.2) (AlSi)2O8 with a low thermal conductivity was prepared through solid-state synthesis. Results show that the (Mg0.5Ca0.3Ba0.2) (AlSi)2O8 solid solution exhibits excellent high-temperature stability and an ultralow thermal conductivity (.3676 W m−1 K−1), far lower than widely used 3YSZ (2.9 W m−1 K−1), La3NbO7 (1.5 W m−1 K−1), and Gd2Zr2O7 (1.28 W m−1 K−1). Furthermore, the Young modulus of the final product is 64.56 GPa. Therefore, the proposed ceramic solid solution provides a new research direction for ultralow thermal conductivity materials and has a practical application value for the field of wall thermal insulation.