Comparison of different tungsten precursors for preparation of tungsten nanopowder by RF induction thermal plasma

Abstract

Tungsten nanopowders were synthesized using three different precursors: commercial tungsten (W), tungsten trioxide (WO3), and ammonium paratungstate (APT) by radio-frequency (RF) induction thermal plasma in the presence and absence of H2. The crystalline structure, morphology, and particle size of the synthesized tungsten nanopowders were analyzed by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The W nanopowder obtained using APT precursor was found to be the most homogeneous and smallest nanoparticles and showed the largest α-W phase (stable) fraction, which is the preferred phase for tungsten because of its superior properties to those of the β-W phase (metastable).