The crystal structure of an oxygen-deficient manganite perovskite LaxSr1−xMnO(5+x)/2 (0≤x≤0.5)

The crystal structure of LaxSr1-xMnO(5+x)/2 was analyzed from the powder diffraction data and Rietveld method. The specimen was prepared by the solid-state reaction method under low oxygen partial pressure. The results of the structural analysis showed several different structures which were modified from perovskite type with ordered arrangement of oxygen vacancies, depending on the composition. (La0.1Sr09MnO2.55)-Mn-. had orthorhombic structure (Pbam) with the lattice dimension of root 2a(p), x 2 root 2a(p) x 1a(p). La0.2Sr0.8MnO2.60 and La 0.3Sr0.7MnO2.65 had a monoclinic structure (P2/m) with the lattice dimension of root 5a(p) x 1a(p) x root 5a(p), La0.4Sr0.6MnO2.70 had a cubic cell (Pm3m) with the lattice dimension of 1a(p) x 1a(p) X lap. La0.5Sr0.5MnO2.75 had a tetragonal structure (I4/mmm) with the lattice dimension of root 2a(p) x root 2a(p) x 2a(p). (c) 2005 Published by Elsevier B.V.