Rapid solid-phase synthesis for tantalum nitride nanoparticles and coatings

• TaN nanoparticles were produced from a (K2TaF7 + 5NaN3) exothermic mixture.
• KF and NH4F were used during the synthesis to control the combustion parameters.
• KF and NH4F were used during the synthesis to control morphology of the final nitride particles.
• The coating of a TaN film via the combustion reaction is briefly reported here.

Tantalum nitride nanoparticles were produced from a (K2TaF7 + 5NaN3) exothermic mixture under the combustion regime. The effects of the K2TaF7/NaN3 ratio and KF and NH4F concentrations on the combustion parameters, product composition, and size of the tantalum nitride particles were studied. Depending on the synthesis conditions, the combustion temperature was maintained in the 700–1200 °C range, resulting in hexagonal ε-TaN, TaN0.8, and Ta2N phases. The dominant phases were TaN and TaN0.8 in the 1000–1200 °C range, whereas only the Ta2N phase was present in the 700–100 °C range. Pure-phase cubic tantalum nitride (δ-TaN) was produced with 4.0 mol of NH4F at a combustion temperature of ~ 800 °C. Under controlled reaction conditions, the size of the tantalum nitride particles was about 10–50 nm. We also found that during the synthesis, the stainless steel tube located inside of the reaction mixture was partially coated with fine TaN crystals. The mechanism of the combustion process is discussed in regards to the experimental results.