Experimental and Modeling Study of the Fabrication of Mg Nano-Sculpted Films by Magnetron Sputtering Combined with Glancing Angle Deposition

Abstract

Today, Mg is foreseen as one of the most promising materials for hydrogen storage when prepared as nano-objects. In this context, we have studied the fabrication of Mg nano-sculpted thin films by magnetron sputtering deposition in glancing angle configuration. It is demonstrated that the microstructure of the material is controllable by tuning important deposition parameters such as the tilt angle or the deposition pressure which both strongly affect the shadowing effect during deposition. As an example, the angle formed by the column and the substrate and the intercolumnar space varies between ~20° to ~50° and ~45 to ~120 nm, respectively, when increasing the tilt angle from 60° to 90°. These observations are highlighted by modeling the growth of the material using kinetic Monte Carlo methods which highlights the role of surface diffusion during the synthesis of the coating. This work is a first step towards the development of an air-stable material for hydrogen storage.

Influence of Thickness and Sputtering Pressure on Electrical Resistivity and Elastic Wave Propagation in Oriented Columnar Tungsten Thin Films

“…Indeed, the high voided microstructure and large spaces between the tilted columns (obtained for the lowest pressures) clearly viewed by SEM analyses (Figure 6a-c) contributed to the global porosity. Although an increase in argon sputtering pressure usually leads to much more porous thin films prepared by conventional sputtering, this reverse trend has previously been reported in Liang et al investigations for Mg films deposited by the GLAD method [58]. The authors also reached the same conclusion, i.e., a decrease in the film porosity due to shorter intercolumnar spaces obtained at high pressure.…”

Recent Advances in the Development of Nano-Sculpted Films by Magnetron Sputtering for Energy-Related Applications

“…Therefore, we will only discuss the results obtained for the Ti films. A detailed description of the Mg case can be found elsewhere [ 32 ], and the cross-sectional SEM images associated with the simulated data are presented in the Supplementary Materials, Figure S4 .…”

“…If the fundamental understanding of the observed phenomenon is the key element motivating our efforts, the applications of the developed materials in a meaningful field such as that of energy-related technologies are equally important. Therefore, the developed nano-sculpted thin films have been employed for energy-related applications such as for the design of novel hydrogen storage materials [ 32 ] or of novel photoanodes in DSSCs. The most important results obtained for the latter case will be summarized in the following pages.…”

“…Evolution of the columnar tilt angle ( β ) as a function of the angle of deposition ( α ) for ( c ) Ti and ( d ) Mg nano-sculpted thin films. The error bars were estimated by taking the tilt average over 20 columns (adapted from [ 50 ] with permission from Elsevier, 2017, and from [ 32 ], MDPI, 2019).…”

Advanced Strategies in Thin Films Engineering by Magnetron Sputtering

“…Liang et al [17] report on the preparation of Mg nano-sculpted thin films by magnetron sputtering, implementing the glancing angle deposition technique. They demonstrate how the microstructure of the film can be tuned by adjusting deposition parameters such as the tilt angle or the sputtering pressure, which both largely influence the shadowing effect during the film deposition.…”