Room-Temperature\nDeposition of δ‑Ni<sub>5</sub>Ga<sub>3</sub> Thin Films\nand Nanoparticles via Magnetron\nSputtering

Magnetron sputtering is a versatile method for investigating\nmodel\nsystem catalysts thanks to its simplicity, reproducibility, and chemical-free\nsynthesis process. It has recently emerged as a promising technique\nfor synthesizing δ-Ni<sub>5</sub>Ga<sub>3</sub> thin films.\nPhysically deposited thin films have significant potential to clarify\ncertain aspects of catalysts by eliminating parameters such as particle\nsize dependence, metal–support interactions, and the presence\nof surface ligands. In this work, we demonstrate the potential of\nmagnetron sputtering for the synthesis and analysis of thin film catalysts,\nusing Ni<sub>5</sub>Ga<sub>3</sub> as a model system. Initially, deposition\nconditions were optimized by varying the deposition pressure, followed\nby an investigation of the temperature effects, aiming to map a structure\nzone dependence on temperature and pressure as in the Thornton model.\nThe evolution of film crystallinity was monitored using a combination\nof grazing incidence X-ray diffraction (GI-XRD) and high-resolution\nscanning electron microscopy (HR-SEM). Additionally, ultrathin films\nwere synthesized and annealed in H<sub>2</sub> at high temperatures\nto demonstrate the possibility of producing size-controlled nanoparticles\nby adjusting the annealing conditions. This work demonstrates the\nfull potential of magnetron sputtering as a technique for synthesizing\nmodel system catalysts in various forms, opening new avenues for the\nresearch and development of additional catalytic systems.