A DFT study of mechanical properties, thermal conductivity and electronic structures of Th-doped Gd2Zr2O7

Abstract A systematic density functional theory study is performed to investigate the mechanical stability, elastic moduli, Debye temperature, thermal conductivity and electronic structures of Gd 2- y Th y Zr 2 O 7 and Gd 2 Zr 2- y Th y O 7 . All the Th-doped Gd 2 Zr 2 O 7 compositions are found to be structurally and mechanically stable. As compared with the pure Gd 2 Zr 2 O 7 , Th incorporation into both Gd-site and Zr-site results in generally better ductility, lower Debye temperature, and reduced thermal conductivity. The reduction in thermal conductivity can be as high as 25–32%, depending on the content of the Th substituent. Our calculations suggest that Th-doped Gd 2 Zr 2 O 7 , especially Gd 2 Zr 2- y Th y O 7 , exhibits better mechanical and thermal properties that are beneficial to its application as thermal barrier coating material at high temperatures than the pure state.