Existence of the Ba2Ti5O12 Phase in Ca‐Doped TiO2‐Rich BaTiO3

A TEM investigation was conducted on the structure of a second phase precipitated between the grains of a polycrystalline TiO2-rich BaTiO3 which was doped with 8 mol% Ca. This phase was identified as Ca-stabilized Ba2Ti5O12 with a 10-layer orthorhombic structure and unit-cell parameters a=0.990, b=1.131, and c=2.330 nm.