Local distortion in LaMnO3 across the Jahn–Teller transition

Abstract We report on an X-ray absorption study on the temperature dependence of the local organisation around Mn 3+ in a high-quality LaMnO 3.00 ceramics. The structural transition is clearly evidenced by modifications on the EXAFS spectra across the Jahn–Teller transition. These modifications are associated with alterations in the MnO 6 polyhedral arrangement. There is no experimental evidence of any reduction of the static disorder in the coordination shell around the Mn 3+ at high temperature. This result supports the hypothesis that the Jahn–Teller transition would correspond to a change from a static and cooperative distortion to a dynamic one, without remotion of the local distortions present in the MnO 6 below the JT temperature.