Structural and Electronic Phase Transitions in Sr1–xCexMnO3 Perovskites
B J Kennedy, P J Saines, Q D Zhou, Z Zhang, M Matsuda and M Miyake
J Solid State Chem 181, 2639-2645 (2008)
The structures of eight members of the series Sr1−xCexMnO3 with 0.075<x<0.4 have been established using synchrotron X-ray powder diffraction. These exhibit the sequence of structures
with increasing Ce content. Unusual peak broadening due to domain wall scattering is observed near the composition-induced first-order cubic–tetragonal transition. The temperature dependence of the structures for three examples x=0.1, 0.2 and 0.35 is described. For the x=0.1 and 0.35 samples evidence for a first-order loss of the orbital ordering associated with a cooperative Jahn–Teller distortion is presented. The onset of the orbitally disordered state is accompanied by a discontinuous reduction in cell volume.