Square coordinated MnO(2)-units in BiMn(7)O(12).
Room temperature high-resolution synchrotron X-ray diffraction (HRSXRD) measurements were carried out on polycrystalline samples of BiMn(7)O(12) and LaMn(7)O(12). Rietveld refinements of HRSXRD data describe the crystal structures of both compounds in the monoclinic space group I2/m. The maximum entropy method-based pattern fitting (MPF) method inversion of HRSXRD data was utilized to obtain the spatial electron density (ED) distribution. Obtained results show clear differences in ED distributions around Mn-O bonds between isomorphic BiMn(7)O(12) and LaMn(7)O(12). The scheme of ED distributions in BiMn(7)O(12) indicates the presence of orbital ordering in the MnO(2) planar arrangement that appears as prominent features in very distorted MnO(12) and MnO(6) polyhedrons in the perovskite related structure of [BiMn(3)](A-site)[Mn(4)](B-site)O(12).
Okamoto
Hiroshi
H
Centre for Materials Science and Nanotechnology, Department of Chemistry,University of Oslo, P.O.Box 1033 Blindern, NO-0315 Oslo, Norway.
Imamura
Naoki
N
Karppinen
Maarit
M
Yamauchi
Hisao
H
Fjellvåg
Helmer
H
D017895:Manganese Compounds / Q000737:chemistry*; D008958:Models, Molecular; D010087:Oxides / Q000737:chemistry*; D017356:Synchrotrons; D014961:X-Ray Diffraction
D017895:Manganese Compounds; D010087:Oxides; C016552:manganese dioxide