Measurement and Simulation of Mechanical and Optical Properties of Sputtered Amorphous SiC Coatings

In this work we report on the extensive characterization of amorphous silicon carbide (alpha-SiC) coatings prepared by physical deposition methods. Our investigation is performed within the perspective application of alpha-SiC as an optical material for high-precision optical experiments and, in particular, in gravitational wave interferometry. We compare the results obtained with two different sputtering systems [a standard radio frequency (rf) magnetron sputtering and an ion-beam sputtering] to grasp the impact of two different setups on the repeatability of the results. After a thorough characterization of structural, morphological, and compositional characteristics of the prepared samples, we focus on a detailed study of the optical and mechanical losses in those materials. Mechanical losses are further investigated from a microscopic point of view by comparing our experimental results with molecular dynamic simulations of the amorphous SiC structure: first we define a protocol to generate a numerical model of the amorphous film, capturing the main features of the real system; then we simulate its dynamical behavior upon deformation in order to obtain its mechanical response.

Automated summary

This work extensively characterizes amorphous silicon carbide coatings prepared by physical deposition methods. The aim is to explore the potential application of alpha-SiC as an optical material in high-precision optical experiments and gravitational wave interferometry. The study compares the results obtained from different sputtering systems to assess their repeatability. After thorough characterization, the focus is on studying the optical and mechanical losses in the materials, with a particular emphasis on the microscopic analysis using molecular dynamic simulations.