Mechanical effects of ion-implanted gold nanoparticles on the surface properties of silica glass

Silica glass (SG) is a highly versatile material used in optics, electronics, construction, and medicine due to its transparency and mechanical properties. However, enhancing its performance poses scientific challenges, especially in reinforcing it while preserving these properties and understanding its deformation under stress. This study investigates the effect of gold nanoparticles (AuNPs) on the mechanical response of SG material. AuNPs were nucleated into high-purity SG using a 3MV Tandem Accelerator Pelletron, followed by thermal annealing at 600°C in an H₂ + N₂ atmosphere. High-resolution transmission electron microscopy (HRTEM) revealed a Gaussian distribution of AuNPs at a depth of ∼450 nm. Nanoindentation tests indicated minor variations in hardness (1.5%) and reduced elastic modulus (4.4%) with AuNP incorporation. Scratch tests demonstrated that the mechanical integrity of the AuNPs/SG sample was preserved when deformation remained below the determined fracture load of SG, although it exhibited a slightly higher coefficient of friction. Finite element analysis provided insights into the strain behavior within the AuNP zone, confirming how AuNPs distribute stress within the SG matrix.