Synthesis and superstructural characterization of Fe[sub 1. 89]Mo[sub 4. 11]O[sub 7]

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1994.0891· OSTI ID:5048165

Schimek, G L; McCarley, R E ^[1]; Chumbley, L S ^[2]

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1. Ames Laboratory, United States Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)
2. Ames Laboratory, United States Department of Energy and Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States)

Superstructuring in the new compound Fe[sub 1.89]Mo[sub 4.11]O[sub 7] has been elucidated by transmission electron microscopy. This compound is a member of the family M[sub 2]Mo[sub 4]O[sub 7] and has both iron and molybdenum atoms occupying octahedrally coordinated sites in the structure, represented by Fe[sup [ital t]](Fe[sub 0.89]Mo[sub 0.11])[sup [ital o]]Mo[sub 4]O[sub 7]. The superstructuring, detected only by electron diffraction, involved tripling of all three lattice parameters of the subcell. The subcell was structured by single crystal x-ray diffraction ([ital Imma], no. 74, [ital a]=5.9793(5)A, [ital b]=5.7704(4)A, and [ital c]=17.036(1)A). This structure type contains a close-packed arrangement of Mo[sub 4]O[sub 7] units, which are infinite chains of trans edge-shared molybdenum octahedra running parallel to [ital b]*. Two different coordination environments are observed for the cations. Parallel to the [ital a]* direction, infinite edge-sharing MO[sub 6] (M=89% Fe or 11% Mo) octahedra are observed. The second cation site, with nearly tetrahedral coordination by oxygen, is filled solely by iron. The superstructure can be rationalized by a regular arrangement of iron and molybdenum atoms in the octahedrally coordinated cation sites.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5048165
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 9:4; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
IRON COMPOUNDS
IRON OXIDES
LATTICE PARAMETERS
MICROSCOPY
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION