Reduction of the Jahn-Teller distortion at the insulator-to-metal transition in mixed valence manganites

Journal Article · Wed Jan 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.34· OSTI ID:432523

Garcia-Munoz, J L; Suaaidi, M; Fontcuberta, J ^[1]; Rodriguez-Carvajal, J ^[2]

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1. Institut de Ciencia de Materials de Barcelona, Consejo Superior de Investigaciones Cientificas Campus, Universitat Autonoma de Barcelona, Bellaterra 08193 (Spain)
2. Laboratoire de Leon-Brillouin (Commissariat a lenergie atomique-Centre National de la Recherche Scientifique), Centre dEtudes de Saclay, 91191 Gif sur Yvette Cedex (France)

The insulator-to-metal transition in the manganite La{sub 0.52}Y{sub 0.15}Ca{sub 0.33}MnO{sub 3} (T{sub IM}{approx}115 K) has been studied by high-resolution neutron powder diffraction. The cell volume contraction at the Curie point is accompanied by a remarkable decrease of the Jahn-Teller distortion in MnO{sub 6} octahedra. The change of the Mn-O bond lengths at T{sub IM} is anisotropic and brings about a drop out of the basal-plane collective distortion mode Q{sub 2}, proposed to be the deformation responsible for the band split of e{sub g{up_arrow}} orbitals. This is consistent with the double-exchange picture, and precludes simple ferromagnetic exchange. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 432523
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 1 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM OXIDES
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
JAHN-TELLER EFFECT
LANTHANUM OXIDES
MANGANESE OXIDES
NEUTRON DIFFRACTION
PHASE STUDIES
YTTRIUM OXIDES