Measurement and simulation of mechanical and optical properties of sputtered amorphous SiC coatings

TL;DR

This study extensively characterizes amorphous silicon carbide coatings, comparing two sputtering methods, and combines experimental and molecular dynamics simulations to analyze their optical and mechanical properties for high-precision optical applications.

Contribution

It introduces a comprehensive comparison of sputtering techniques and integrates experimental data with molecular dynamics simulations to understand a-SiC coatings' properties.

Findings

Different sputtering setups affect coating properties.

Simulations successfully replicate mechanical behavior.

a-SiC shows promise for optical applications in gravitational wave detection.

Abstract

In this work We report on the extensive characterization of amorphous silicon carbide (a-SiC) coatings prepared by physical deposition methods. We compare the results obtained on two different sputtering systems (a standard RF magnetron sputtering and a ion-beam assisted sputtering) to seize the impact of two different setups on the repeatably 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 behaviour upon deformation in order to obtain its mechanical response. Our results are discussed within the perspective application of a-SiC as an optical material for high-precision optical experiments and in particular in gravitational wave interferometry.