Neutron and X-ray powder diffraction studies of LiMn{sub 2{minus}y}Cr{sub y}O{sub 4}

Journal Article · Wed Sep 01 04:00:00 EDT 1999 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1999.8351· OSTI ID:696667

Oikawa, K; Kamiyama, T ^[1]; Izumi, F ^[2]; Nakazato, D; Ikuta, H; Wakihara, M ^[3]

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1. Univ. of Tsukuba, Ibaraki (Japan). Inst. of Materials Science
2. National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)
3. Tokyo Inst. of Tech., Ookayama, Meguro (Japan). Dept. of Chemical Engineering

The crystal structures of chromium-doped spinel-type lithium manganese oxides, LiMn{sub 2{minus}y}Cr{sub y}O{sub 4} (y = 0, 1/9, 1/6, and 1/3), have been studied by neutron and X-ray powder diffraction. Rietveld refinements of their neutron diffraction data revealed that Cr is substituted for Mn selectively and that Li occupies only the 8a site. Thus, the above solid solutions can be expressed as Li(Mn{sub 2{minus}y}Cr{sub y})O{sub 4}. The fractional coordinates of oxygen were almost the same in all the samples while the lattice parameter a decreased linearly with increasing Cr content. The lengths of (Mn, Cr)-O bonds in (Mn, Cr)O{sub 6} octahedra changed in a manner expected from average ionic radii for Mn{sub 2{minus}y}Cr{sub y}. Rietveld analyses of the X-ray diffraction data showed the crystallite size and anisotropic strain to decrease with increasing Cr content.

• OSTI ID: 696667
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 146; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM OXIDES
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
LATTICE PARAMETERS
LITHIUM OXIDES
MANGANESE OXIDES
NEUTRON DIFFRACTION
SOLID SOLUTIONS
STOICHIOMETRY
X-RAY DIFFRACTION