Neutron Powder Diffraction Study on the Crystal and Magnetic Structures of BiCrO3

The crystal and magnetic structures of polycrystalline BiCrO3 were determined by the Rietveld method from neutron diffraction data measured at temperatures from 7 to 490 K. BiCrO3 crystallizes in the orthorhombic system above 420 K (space group Pnma; Z = 4; a = 5.54568(12) Å, b = 7.7577(2) Å, and c...

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Bibliographic Details
Published in:Chemistry of materials 2008-06, Vol.20 (11), p.3765-3769
Main Authors: Belik, Alexei A, Iikubo, Satoshi, Kodama, Katsuaki, Igawa, Naoki, Shamoto, Shinichi, Takayama-Muromachi, Eiji
Format: Article
Language:English
Subjects:
Inorganic Solids and Ceramics
Structural Characterization (including AFM, NMR, X-ray Diffraction, etc.)
Online Access:Get full text
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Summary:The crystal and magnetic structures of polycrystalline BiCrO3 were determined by the Rietveld method from neutron diffraction data measured at temperatures from 7 to 490 K. BiCrO3 crystallizes in the orthorhombic system above 420 K (space group Pnma; Z = 4; a = 5.54568(12) Å, b = 7.7577(2) Å, and c = 5.42862(12) Å at 490 K) in the GdFeO3-type structure. Below 420 K down to 7 K, a monoclinic structure is stable with C2/c symmetry (a = 9.4641(4) Å, b = 5.4790(2) Å, c = 9.5850(4) Å, and β = 108.568(3)° at 7 K). A possible model for antiferromagnetic order below T N = 109 K is proposed with a propagation vector of k = (0, 0, 0). In this model, magnetic moments of Cr3+ ions are coupled antiferromagnetically in all directions, forming a G-type antiferromagnetic structure. Refined magnetic moments at 7, 50, and 80 K are 2.55(2)μB, 2.43(2)μB, and 2.09(2)μB, respectively. The structure refinements revealed no deviation from stoichiometry in BiCrO3.
ISSN:0897-4756
1520-5002
DOI:10.1021/cm800375d