Synthesis of tungsten nitrides and carbide nitrides

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:560227

Zhang, Zhihong; McCarley, R E ^[1]

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1. Ames Lab., IA (United States)

Efforts to prepare the unknown, metastable tungsten(VI) nitride WN{sub 2} have proceeded with various reactions of WNCl{sub 3} conducted under mild conditions. Reactions of WNCl{sub 3} with Zn{sub 3}N{sub 2} in sealed tubes at 400{degrees}C frequently failed because of explosions. Under careful management of composition of the reaction mixture and temperature programming, however, the reactions were successfully completed to provide amorphous W{sub 3}N{sub 5}. Annealing of the latter at 800{degrees}C in a sealed silica tube resulted in decomposition into a mixture of W and hexagonal WN, as well as growth by chemical transport of a few crystals of the new nitride carbide WN{sub 2}C, based upon single crystal x-ray structure analysis. Reaction of WNCl{sub 3} with Ca{sub 3}N{sub 2} in acetonitrile at 80{degrees}C results in a precursor which can be converted at 500{degrees}C into the new metastable cubic-WN with the rock salt structure. The explosive azido precursor WN(N{sub 3}){sub 3}{sm_bullet}xCH{sub 3}CN can be obtained by reaction of WNCl{sub 3} with NaN{sub 3} in acetonitrile at 20{degrees}C, and successfully converted to nitrido products in situ. Some reactions of WN(N{sub 3}){sub 3}{sm_bullet}xCH{sub 3}CN will be discussed.

• OSTI ID: 560227
• Report Number(s): CONF-970443--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACETONITRILE
ANNEALING
CRYSTAL STRUCTURE
NITROGEN CHLORIDES
PRECURSOR
SYNTHESIS
TUNGSTEN CHLORIDES
TUNGSTEN NITRIDES