Orbital Correlations in the Pseudocubic O and Rhombohedral R Phases of LaMnO{sub 3}

Journal Article · Fri May 06 04:00:00 EDT 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.94.177203· OSTI ID:20696248

Xiangyun, Qiu; Billinge, S J.L. ^[1]; Proffen, Th ^[2]; Mitchell, J F ^[3]

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1. Department of Physics and Astronomy, Michigan State University, E. Lansing, Michigan 48824 (United States)
2. Los Alamos National Laboratory, LANSCE-12, MS H805, Los Alamos, New Mexico 87545 (United States)
3. Material Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

The local and intermediate structure of stoichiometric LaMnO{sub 3} has been studied in the pseudocubic and rhombohedral phases at high temperatures (300-1150 K). Neutron powder diffraction data were collected and a combined Rietveld and high real space resolution atomic pair distribution function analysis was carried out. The nature of the Jahn-Teller (JT) transition around 750 K is confirmed to be orbital order to disorder. In the high-temperature orthorhombic (O) and rhombohedral (R) phases, the MnO{sub 6} octahedra are still fully distorted locally. More importantly, the intermediate structure suggests the presence of local ordered clusters of diameter {approx}16 A ring ({approx}4 MnO{sub 6} octahedra) implying strong nearest-neighbor JT antiferrodistortive coupling. These clusters persist well above the JT transition temperature even into the high-temperature R phase.

• OSTI ID: 20696248
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 17 Vol. 94; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
CORRELATIONS
DISTRIBUTION FUNCTIONS
INTERMEDIATE STRUCTURE
JAHN-TELLER EFFECT
LANTHANUM COMPOUNDS
MANGANATES
MANGANESE OXIDES
NEUTRON DIFFRACTION
ORDER-DISORDER TRANSFORMATIONS
SPATIAL RESOLUTION
STOICHIOMETRY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TRANSITION TEMPERATURE