Local scale ordering in LaMnO3 under pressure: x-ray absorption study

Aline Y. Ramos (1) , Hélio Tolentino (2) , Narcizo M. Souza-Neto (3) , Alberto Caneiro (4, 5) , Yves Joly (6) , Jean-Paul Itié (7) , Anne-Marie Flank (7) , Pierre Lagarde (7)

1 NEEL - MRS - Matériaux, Rayonnements, Structure
2 NEEL - CRG - CRG & Grands instruments
3 Advanced Photon Source
4 Centro Atómico Bariloche [Argentine]
5 Instituto Balseiro [Bariloche]
6 NEEL - SIN - Surfaces, Interfaces et Nanostructures
7 SSOLEIL - Synchrotron SOLEIL

The present study aims, by using X-ray Absorption Spectroscopy, to describe the local process towards the pressure-induced abrupt changes in the resistivity in the Jahn-Teller distorted LaMnO3 doped compounds. Local environment of manganese atoms under pressure up to 37 GPa has been studied by X-ray absorption spectroscopy. We identify successive steps towards the pressure-induced abrupt changes in the resistivity. These steps are associated to local processes such as the opening of the inter-octahedra tilt angles and the average symmetrization of the Mn local environment. All modifications present a hysteretic behavior when the pressure is released, pointing to the coexistence of MnO6 distorted and undistorted units.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Aline Y. Ramos, Hélio Tolentino, Narcizo M. Souza-Neto, Alberto Caneiro, Yves Joly, et al.. Local scale ordering in LaMnO3 under pressure: x-ray absorption study. Journal of Physics: Conference Series, 2009, 190, pp.012096. ⟨10.1088/1742-6596/190/1/012096⟩. ⟨hal-00443724⟩