Work

Morphology and yield of W nanoparticles in gas aggregation: Pathways towards functional nanocomposite films

Year: 2025

Type: article

Abstract: While gas aggregation cluster sources can tailor the chemistry, size, and shape of nanoparticles (NPs), low NP yield and instability over time still limit the fabrication of nanoparticle-based coatings or nanocomposite films. In this work, we propose controlled addition of ambient air as a nucleation source to enhance the efficiency and stability of the process. Additionally, the type of power source is varied, juxtaposing direct current and high-power impulse magnetron sputtering. Quadruple mass spectrometry and high-resolution transmission electron microscopy are used to monitor the deposition rate and morphology of tungsten NPs (size, shape, microstructure) as a function of process parameters. We observe significant variations in the deposition rate, the average diameter (3–5 nm), and the microstructure (amorphous vs. single-crystalline) of produced W NPs. The enhanced NP flux was exploited to demonstrate fast deposition of 500 nm thick W nanoparticle films as well as 200 nm thick nanocomposite films, consisting of a Cu matrix with incorporated W nanoparticles. For the latter we attribute refinement of the Cu matrix microstructure to two competing mechanisms: Formation of growth twins facilitated by W NPs and grain refinement due to residual air.

Source: Surface and Coatings Technology

DOI: 10.1016/j.surfcoat.2025.133089