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Stability of Jahn Teller distortion in LaMnO3 under pressure: An x-ray absorption study

Aline Y. Ramos·Hélio C. N. Tolentino·Narcizo M. Souza-Neto·Jean-Paul Itié·Liliana Morales·Alberto Caneiro
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Abstract

The local environment of manganese atoms in LaMnO3 under pressure up to 15.3 GPa has been studied by x-ray absorption spectroscopy. For pressures below 8 GPa, no change is detected within the MnO6 octahedra. Above this pressure a continuous reduction of the long Mn-O distance takes place, however the octahedral distortion persists over the whole pressure range. At 15.3 GPa the average Jahn-Teller splitting of the distances is reduced by about one third, indicating that a total removal of the local Jahn-Teller distortion would occur only for pressures around 30 GPa, where metallization is reported to take place. A hysteresis in the long distance reduction is observed down to ambient pressure, suggesting the coexistence of MnO6 distorted and undistorted units.

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Aline Y. Ramos, Hélio C. N. Tolentino, Narcizo M. Souza-Neto, Jean-Paul Itié, Liliana Morales, Alberto Caneiro. 2007-01-30. Stability of Jahn Teller distortion in LaMnO3 under pressure: An x-ray absorption study. https://doi.org/10.1103/physrevb.75.052103

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