Preparation of HfNbTiTaZr Thin Films by Ionized Jet Deposition Method

Abstract

The ionized jet deposition (IJD) method is applied to the preparation of thin films composed of refractory HfNbTiTaZr high-entropy alloy (HEA). Due to its stoichiometric reliability, the IJD method provides a flexible tool for deposition of complex multi-element materials, such as HEAs. Scanning electron microscopy, energy-dispersion spectroscopy, confocal microscopy, and X-ray diffraction methods are used to characterize the influence of the applied accelerating voltage of the IJD deposition head ranging from 16 to 22 kV on the resulting morphology, chemical composition, thickness, crystalline structure, and phase composition of the layers prepared as 10 mm-wide strips on a single stainless-steel substrate. With a low accelerating voltage applied, the best surface homogeneity is obtained. Transfer coefficient values characterizing the elemental transport between the bulk target and the grown layer are evaluated for each constituting element and applied voltage. With the IJD accelerating voltage approaching 22 kV, the coefficients converge upon the values proportional to the atomic number of the element. Such voltage dependence of the IJD elemental transport might be used as a suitable tool for fine-tuning the elemental composition of layers grown from a single deposition target.