  Based on Landau-Devonshire (LD) phenomenological theory, phase diagram of
epitaxial BST50/50 thin films on anisotropic in-plane strains is investigated.
Different from BaTiO3 thin films, the paraelectric phase appears under the
anisotropic misfit strains on BST50/50 thin films at the room temperature. The
pyroelectric property of the BST films is also calculated, we find that the
position of pyroelectric peak greatly depends on anisotropic misfit strains.
Keywords: anisotropic in-plane strains; BST thin films; phase diagram
