Room-Temperature Deposition of δ-Ni5Ga3 Thin Films and Nanoparticles via Magnetron Sputtering

Abstract

Magnetron sputtering is a versatile method for investigating model system catalysts thanks to its simplicity, reproducibility, and chemical-free synthesis process. It has recently emerged as a promising technique for synthesizing δ-Ni₅Ga₃ thin films. Physically deposited thin films have significant potential to clarify certain aspects of catalysts by eliminating parameters such as particle size dependence, metal–support interactions, and the presence of surface ligands. In this work, we demonstrate the potential of magnetron sputtering for the synthesis and analysis of thin film catalysts, using Ni₅Ga₃ as a model system. Initially, deposition conditions were optimized by varying the deposition pressure, followed by an investigation of the temperature effects, aiming to map a structure zone dependence on temperature and pressure as in the Thornton model. The evolution of film crystallinity was monitored using a combination of grazing incidence X-ray diffraction (GI-XRD) and high-resolution scanning electron microscopy (HR-SEM). Additionally, ultrathin films were synthesized and annealed in H₂ at high temperatures to demonstrate the possibility of producing size-controlled nanoparticles by adjusting the annealing conditions. This work demonstrates the full potential of magnetron sputtering as a technique for synthesizing model system catalysts in various forms, opening new avenues for the research and development of additional catalytic systems.