Single crystal structural study of the charge ordered phase of Pr0.6Ca0.4MnO3: electronic localization beyond the atomic level
Abstract
In the R1/2D1/2MnO3 manganites (R: rare earth, D: divalent cation), the structural phase transition at Tco is commonly interpreted as a concomitant charge and orbital ordering (CO/OO) process driven by a cooperative Jahn-Teller effect and Coulomb repulsion forces. Full crystal structure refinement, from a neutron diffraction experiment below Tco on a Pr0.6Ca0.4MnO3 single crystal, gives us a model for the displacement of atoms with respect to the high temperature (HT) phase that invalidates the standard model based on the CO/OO picture. An alternative picture is that the phase transition and charge localization at Tco arise from a spatially ordered condensation of ferromagnetic Mn-Mn pairs, in which Mn atoms keeps an intermediate valence state.
- Publication:
-
arXiv e-prints
- Pub Date:
- November 2001
- DOI:
- 10.48550/arXiv.cond-mat/0111267
- arXiv:
- arXiv:cond-mat/0111267
- Bibcode:
- 2001cond.mat.11267D
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 5 pages, 3 figures, revetex4