The Checkerboard Pattern of the Charge‐Ordered Phases in Bi1−xSrxMnO3 (x⩽0.5) Studied by Resonant X‐Ray Scattering at the Mn K Edge

We report here resonant x‐ray scattering (RXS) experiments carried out at the Mn K edge in Bi1−xSrxMnO3 (x=0.3, 0.5) single‐crystals at room temperature. These compounds show a so‐called charge ordered (CO) state at room temperature. Strong resonances were observed as the photon energy is tuned through the Mn K‐edge for several weak superstructure (h 0 0) and (0 k 0) and forbidden (h/2 0 0) and (0 k/2 0) reflections with h, k odd within the a‐b plane (Ibmm setting) in the x=0.3 and x=0.5 compounds, respectively. The reported azimuth angle and polarization dependences of the resonant intensity for the complete set of reflections point out to a structural transition at TCO that stabilizes a checkerboard ordering of two non‐equivalent Mn atoms with different local geometrical structures. We conclude that the checkerboard ordered phase is a common ground state in the so‐called CO manganites, A1−xBxMnO3, independently of the nature of the A and B atoms and for compositions x even far from 0.5. Moreover, the qu...