Crystal structure of Bi{sub 1-x}Tb{sub x}FeO{sub 3} from high-resolution neutron diffraction

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.04.028· OSTI ID:21580111

Saxin, Stefan ^[1]

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1. Department of Chemistry, University of Gothenburg, SE-412 96 Goeteborg (Sweden)

Samples of Bi{sub 1-x}Tb{sub x}FeO{sub 3}, with x=0.05, 0.10, 0.15, 0.20 and 0.25, have been synthesised by solid state reaction. The crystal structures of the perovskite phases, characterised via Rietveld analysis of high resolution powder neutron diffraction data, reveal a structural transition from the R3c symmetry of the parent phase BiFeO{sub 3} to orthorhombic Pnma symmetry, which is complete for x=0.20. The x=0.10 and 0.15 samples are bi-phasic. The transition from a rhombohedral to orthorhombic unit cell is suggested to be driven by the dilution of the stereochemistry of the Bi{sup 3+} lone pair at the A-site. The G-type antiferromagnetic spin structure, the size of the ordered magnetic moment ({approx}3.8 {mu}{sub B}) and the T{sub N} ({approx}375 deg. C) are relatively insensitive to increasing Tb concentrations at the A-site. - Graphical abstract: High resolution neutron powder diffraction has been used to study the evolution of the RT crystal structure of Bi{sub 1-x}Tb{sub x}FeO{sub 3} (0.05{<=}x{<=}0.25) with terbium content. A transition from polar R3c to centrosymmetric Pnma symmetry is observed. The antiferromagnetic ordering temperature and size of the ordered magnetic moment are relatively insensitive to the change of crystal structure. Highlights: > Structural transition from polar R3c symmetry to non-polar Pnma symmetry occurs. > Behaviour is rationalised via dilution of the stereochemical nature of the Bi lone pair. > Magnetic properties are largely unaffected.

• OSTI ID: 21580111
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 6 Vol. 184; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
BISMUTH IONS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
IONS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETISM
MINERALS
NEUTRON DIFFRACTION
ORTHORHOMBIC LATTICES
OXIDE MINERALS
PEROVSKITE
PEROVSKITES
PHYSICAL PROPERTIES
SCATTERING
SOLIDS
STEREOCHEMISTRY
SYMMETRY
TRIGONAL LATTICES