Structural characterization of the perovskite series Sr{sub 1−x}La{sub x}Ti{sub 0.5}Mn{sub 0.5}O{sub 3}

The perovskite-type compounds Sr{sub 1−x}La{sub x}Ti{sub 0.5}Mn{sub 0.5}O{sub 3}, x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 have been synthesized by solid-state methods, and their room temperature structures determined using X-ray synchrotron powder diffraction. The x=0.0 end member, SrMn{sub 0.5}Ti{sub 0.5}O{sub 3} is cubic in space group Pm3{sup ¯}m; there being no evidence for ordering of the Ti{sup 4+} and Mn{sup 4+} cations. We find that x=0.5 compound is rhombohedral in R3{sup ¯}c rather than orthorhombic as reported previously. Magnetic measurements suggest that both SrMn{sub 0.5}Ti{sub 0.5}O{sub 3} and Sr{sub 0.5}La{sub 0.5}Mn{sub 0.5}Ti{sub 0.5}O{sub 3} are spin-glasses. - Graphical abstract: A cubic–rhombohedral phase-transition is observed cation disordered perovskites Sr{sub 1−x}La{sub x}Ti{sub 0.5}Mn{sub 0.5}O{sub 3}. Both end members are spin-glasses. Highlights: ► Structural studies of Sr{sub 1−x}La{sub x}Ti{sub 0.5}Nb{sub 0.5}O{sub 3} perovskites, show lack of long range Mn:Ti order. ► Magnetic properties indicative of spin-glass behavior. ► Changes of crystal structure from cubic to rhombohedral with increasing lanthanum content.