Modeling thermodynamic stability of morphologies and surfaces of YF3

Shape and size of YF3 particles are determinant in hydrothermal synthesis experiments, whereas the surfaces’ structural and thermodynamic parameters are largely unknown but are indispensable for further optimizations to the YF3 micro- and nanocrystals. In this work we focus on {020}, {111}, {101¯} and {1¯02} facets that are frequently observed. For each orientation, structures and surface energies are obtained using density functional theory calculations. The surface energies are found to be in the order of {020}<{111}<{101¯}<{1¯02}. The Wulff shape is truncated octahedron, and may expose {1¯02} facets under fluorine-lean conditions. For other experimentally observed shapes (octahedron and diamond-like polyhedron), we present necessary modifications to the surface energies through the inverse Wulff construction method. The results are expected to be helpful in choosing surface-specific surfactants in synthesizing YF3 crystals with targeted morphologies.