TY - JOUR
T1 - Synthesis of ΝbN faceted grains from oxides and boron nitride with sodium
AU - Yamada, Takahiro
AU - Kuge, Naoya
AU - Sekiya, Toru
AU - Yamane, Hisanori
N1 - Funding Information:
This work was financially supported in part by a Japan Society for the Promotion of Science , (KAKENHI; grant number JP20K21231 ). The authors would like to thank Takashi Kamaya (Tohoku University) for SEM and EPMA measurements.
Funding Information:
This work was financially supported in part by a Japan Society for the Promotion of Science, (KAKENHI; grant number JP20K21231). The authors would like to thank Takashi Kamaya (Tohoku University) for SEM and EPMA measurements.
Publisher Copyright:
© 2023 Elsevier Ltd and Techna Group S.r.l.
PY - 2023
Y1 - 2023
N2 - Agglomerates of ε-NbN hexagonal prismatic faceted grains with a size between 5 and 50 μm were formed by heating Nb2O5 or NbFeO4 powder and Na lump in a BN crucible at 900–1100 °C under an Ar atmosphere. Wavelength-dispersive X-ray analysis demonstrated that the ε-NbN faceted grains have a nearly stoichiometric composition. In addition to the ε-NbN grains, powders of niobium nitrides containing δ-NbN and Nb2N, and water-soluble Na3BO3 were included in the sample prepared from Nb2O5 at 1100 °C, while powders of Fe and Na3BO3, and a trace of δ-NbN were included in the sample from NbFeO4. These reactions were attributed to metathesis reactions in which the oxygen in the oxides and the nitrogen in the solid nitrogen source, BN, were replaced by the formation of Na3BO3. An extra amount of nitrogen supplied from the starting material enhances the formation of ε-NbN and suppressed the formation of δ-NbN and Nb2N.
AB - Agglomerates of ε-NbN hexagonal prismatic faceted grains with a size between 5 and 50 μm were formed by heating Nb2O5 or NbFeO4 powder and Na lump in a BN crucible at 900–1100 °C under an Ar atmosphere. Wavelength-dispersive X-ray analysis demonstrated that the ε-NbN faceted grains have a nearly stoichiometric composition. In addition to the ε-NbN grains, powders of niobium nitrides containing δ-NbN and Nb2N, and water-soluble Na3BO3 were included in the sample prepared from Nb2O5 at 1100 °C, while powders of Fe and Na3BO3, and a trace of δ-NbN were included in the sample from NbFeO4. These reactions were attributed to metathesis reactions in which the oxygen in the oxides and the nitrogen in the solid nitrogen source, BN, were replaced by the formation of Na3BO3. An extra amount of nitrogen supplied from the starting material enhances the formation of ε-NbN and suppressed the formation of δ-NbN and Nb2N.
KW - A. Grain growth
KW - A. powders: chemical preparation
KW - D. Nitrides
KW - Solid nitrogen source
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U2 - 10.1016/j.ceramint.2023.01.042
DO - 10.1016/j.ceramint.2023.01.042
M3 - Article
AN - SCOPUS:85146315356
SN - 0272-8842
JO - Ceramics International
JF - Ceramics International
ER -