Synthesis of Non-Cubic Nitride Phases of Va-Group Metals (V, Nb, and Ta) from Metal Powders in Stream of NH3 Gas under Concentrated Solar Radiation

SHOHOJI, Nobumitsu; Oliveira, F. A. Costa; Galindo, José; Rodríguez, José; Cañadas, Inmaculada; Fernandes; Rosa, Luis G.

http://hdl.handle.net/10400.21/14821

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Authors

SHOHOJI, Nobumitsu

Oliveira, F. A. Costa

Abstract(s)

Using a high-flux solar furnace, loosely compacted powders of Va-group transition metal (V, Nb, and Ta) were reacted with stream of NH3 gas (uncracked NH3 gas) being heated by concentrated solar beam to a temperature (T) range between 600 and 1000 °C. From V, sub-nitride V2N (γ phase) and hypo-stoichiometric mono-nitride VN possessing fcc (face-centered cubic) crystal lattice structure (δ phase) were synthesized. On the other hand, in the reaction product from Nb and Ta, hexagonal mono-nitride phase with N/M atom ratio close to 1 (ε phase) was detected. The reaction duration was normalized to be 60 min. In a conventional industrial or laboratory electric furnace, the synthesis of mono-nitride phase with high degree of crystallinity that yield sharp XRD peaks for Va-group metal might take a quite long duration even at T exceeding 1000 °C. In contrast, mono–nitride phase MN of Va-group metal was synthesized for a relatively short duration of 60 min at T lower than 1000 °C being co-existed with lower nitride phases.

Keywords

Concentrated solar radiation Uncracked NH3 gas Nitride Vanadium Niobium Tantalum

URI

http://hdl.handle.net/10400.21/14821

Citation

SHOHOJI, Nobumitsu; [et al] – Synthesis of Non-Cubic Nitride Phases of Va-Group Metals (V, Nb, and Ta) from Metal Powders in Stream of NH3 Gas under Concentrated Solar Radiation. ChemEngineering. ISSN 2305-7084. Vol. 5, N.º 2 (2021), pp. 1-11.