Study of ammonolysis reactions with in situ X-ray diffraction: Detection and crystal structure of Li{sub 0.84}W{sub 1.16}N{sub 2}

Journal Article · Mon Jun 01 04:00:00 EDT 1998 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1998.7767· OSTI ID:642230

Kaskel, S; Hohlwein, D; Straehle, J ^[1]

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1. Univ. Tuebingen (Germany)

The new ternary nitride Li{sub 0.84}W{sub 1.16}N{sub 2} was found by an in situ X-ray diffraction study of the ammonolysis of a LiF-WO{sub 3} mixture. The ammonolysis proceeds via Li{sub 6}W{sub 2}O{sub 9} to LiWN{sub 2}, which subsequently decomposes at 900 C to form Li{sub 0.84}W{sub 1.16}N{sub 2}. For a larger scale synthesis of Li{sub 0.84}W{sub 1.16}N{sub 2}, the ammonolysis of a mixture of Li{sub 2}CO{sub 3} and WO{sub 3} was performed at 900 C. Li{sub 0.84}W{sub 1.16}N{sub 2} crystallizes in the anti-TiP type structure with the space group P6{sub 3}/mmc and a = 2.8809(1) {angstrom}, c = 10.3456(4) {angstrom}, and Z = 2 as determined from simultaneous Rietveld refinement of X-ray and neutron powder diffraction data. The refinement converged with R(F{sup 2}) = 7.0% for the X-ray data and 8.3% for the neutron data with a total reduced {chi}{sup 2} = 3.54. The structure consists of alternating layers of WN{sub 6} trigonal prisms and Mn{sub 6} octahedra (M = W, Li), with distances W-N = 2.11 {angstrom}.

• Sponsoring Organization: Deutsche Forschungsgemeinschaft, Bonn (Germany)
• OSTI ID: 642230
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 138; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMMONOLYSIS
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
LATTICE PARAMETERS
LITHIUM NITRIDES
SYNTHESIS
TUNGSTEN NITRIDES
X-RAY DIFFRACTION