Synthesis under high-oxygen pressure, magnetic and structural characterization from neutron powder diffraction data of YGa{sub 1-x}Mn{sub 1+x}O{sub 5} (x = 0.23): A comparison with YMn{sub 2}O{sub 5}

Journal Article · Tue Feb 05 00:00:00 EST 2008 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2007.10.029· OSTI ID:21068184

Calle, C de la , ^[1]; Alonso, J A; Martinez-Lope, M J; Garcia-Hernandez, M ^[1]; Andre, G ^[2]

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1. Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain)
2. Laboratoire Leon Brillouin, CEA Saclay, F-9119 Gif sur Ivette (France)

A new material of nominal stoichiometry YGaMnO{sub 5} has been prepared in polycrystalline form from citrate precursors followed by thermal treatments under high-oxygen pressure. This compound has been characterized from neutron powder diffraction (NPD) data and magnetic measurements. For comparison, the parent compound YMn{sub 2}O{sub 5} has also been synthesized and its crystal structure refined by NPD data. The new oxide has an actual stoichiometry YGa{sub 1-x}Mn{sub 1+x}O{sub 5} (x = 0.23), determined by NPD, showing an important cationic disorder between both metal sites; it is orthorhombic, Pbam (SG), and its crystal structure contains chains of Mn{sup 4+}O{sub 6} edge-sharing octahedra, linked together by Ga{sup 3+}O{sub 5} pyramids and YO{sub 8} units. With respect to YMn{sub 2}O{sub 5}, containing axially elongated MnO{sub 5} pyramids due to the Jahn-Teller effect of Mn{sup 3+} cations, the GaO{sub 5} pyramidal units in YGa{sub 0.77}Mn{sub 1.23}O{sub 5} are substantially flattened. This compound has a paramagnetic behaviour with two weak anomalies at about 50 K and 350 K. The magnetic structures, studied at 1.4 K and 100 K show a ferromagnetic coupling along the chains of MnO{sub 6} octahedra.

• OSTI ID: 21068184
• Journal Information: Materials Research Bulletin, Vol. 43, Issue 2; Other Information: DOI: 10.1016/j.materresbull.2007.10.029; PII: S0025-5408(07)00475-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPARATIVE EVALUATIONS
GALLIUM COMPOUNDS
GALLIUM IONS
HEAT TREATMENTS
JAHN-TELLER EFFECT
MANGANESE COMPOUNDS
MANGANESE IONS
NEUTRON DIFFRACTION
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN
PARAMAGNETISM
POLYCRYSTALS
SYNTHESIS
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
YTTRIUM COMPOUNDS