Unveiling surface stability and oxygen vacancy segregation of Yb₂SiO₅ and Lu₂SiO₅ by first‐principles calculations

Abstract RE 2 SiO 5 ( = Yb and Lu) are significant environmental barrier coating (EBC) materials, in which surface oxygen vacancy play crucial roles their structural stability functionality. In this work, the configuration thermodynamics of (1 0 0), (0 1 1) surfaces investigated by first‐principles calculations. The is preferred energetically, attributed to weak bond broken environment large rare‐earth polyhedron distortion on surface. Moreover, formation energies various vacancies stable estimated optimal location for held [SiO 4 ] tetrahedron. more likely segregate because lower compared with those bulk. These findings expected enable development ‐based EBCs tuning grain size and/or thin film growth orientation.