Fabrication of Ni@Ti core–shell nanoparticles by modified gas aggregation source

Abstract

Ni@Ti core–shell nanoparticles were prepared by a vacuum based method using the gas aggregation source (GAS) of nanoparticles. Ni nanoparticles fabricated in the GAS were afterwards coated by a Ti shell. The Ti shell was deposited by means of magnetron sputtering. The Ni nanoparticles were decelerated in the vicinity of the magnetron to the Ar drift velocity in the second deposition chamber. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy analysis of the nanoparticles showed the core–shell structure. It was shown that the thickness of the shell can be easily tuned by the process parameters with a maximum achieved thickness of the Ti shell ~2.5 nm. The core–shell structure was confirmed by the STEM analysis of the particles.