Synthesis and structure of (Ca,Sr)-substituted lanthanum manganite

The phase composition and structure of equilibrium LaMnO3-CaMnO3-SrMnO3 samples prepared at 1500 degrees C in air are investigated. The results demonstrate that the system contains a broad region of La1-x(Ca1-ySry)(x)MnO3 perovskite-like solid solutions in which calcium and strontium cations substitute for lanthanum. The solid solutions have an orthorhombic (Pnma), rhombohedral (R (3) over barc), or tetragonal (I4/mcm) structure, depending on the A-site cation composition and the nature of lattice distortions. The composition regions of these structures and two-phase regions are mapped out in the LaMnO3-CaMnO3-SrMnO3 phase diagram.