Diverse tungsten nanoparticles via arc discharge

We have discussed the fabrication of tungsten nanoparticles (W Nps) using arc discharge as a novel technique. Our research focused on optimizing operation parameters such as the applied current and media. The size, morphology and the crystalline phase (αα- vs  . ββ-W Nps) are altered by changing the applied currents (40–160 A), as well as the employed media (gaseous nitrogen, open air, distilled water, and ethylene glycol— all free of any surfactant or stabilizer). Gaseous nitrogen at 100 A provides the best recipe for the arc fabrication of relatively purest, most dispersed, body-centered cubic (bcc) αα-W Nps with rather small average size of 68 nm, determined by TEM, SEM, and XRD analyses. Regardless of the medium used, mixed αα- and ββ-W Nps are encountered at lower currents. In contrast, only the stable metallic αα-W form is observed, at higher currents (80–160 A). Arc discharge is found as a rather convenient, inexpensive, easy and versatile method, for the fabrication of desired W Nps.