Crystal structure phase separation in anion-deficient LaSrMnO manganite system

The crystal structure of anion-deficient LaSrMnO manganite powders (δ = 0, 0.10, 0.15, 0.20) has been investigated at room temperature by the neutron diffraction method using a high-resolution Fourier diffractometer. The structure data have been refined by the Rietveld method. The crystal structures of the stoichiometric LaSrMnO and anion-deficient LaSrMnO manganites are satisfactorily described by the rhombohedral space group . A small amount of the non-perovskite MnO phase (space group ) has been found for the anion-deficient LaSrMnO sample. It has been found that the anion-deficient LaSrMnO sample consists of two perovskite phases described by space groups and 4/ and the MnO phase (space group ). The crystal structure of the anion-deficient LaSrMnO sample is described by one perovskite phase with space group 4/. The volume fraction of the MnO phase is ≪1% for all anion-deficient samples. Oxygen vacancies in the anion-deficient LaSrMnO manganite system stimulate the structure phase separation at 293 K.