Interdiffusion processes between aluminum enriched PVD-sputtered silica thin films and industrial float soda-lime silicate glass substrates are quantitatively studied using SIMS analysis. Heat treatments are performed at temperatures close or above the glass transition temperature of the float glass. Aluminum doping of the film is shown to strongly increase the migration of alkali from the glass substrate to the silica thin film. In particular the final alkali content in the film exhibits a linear scaling with the aluminum concentration. An interdiffusion process is evidenced between bulk alkali ions and protons originating from a significant water content in the as-deposited silica film. Experimental measurements of sodium concentration are shown to be consistent with a simple thermodynamic model based on the equilibration of the activity of sodium between the film and the glass substrate. K E Y W O R D Sdiffusion/diffusivity, silica, soda-lime-silica, thermal treatment, thin films

We study the diffusive interaction between soda‐lime glass substrates and sputtered aluminum‐doped silica thin films at 650°C, the temperature of commercial soda‐lime glass shaping or tempering. A first rapid migration of alkali ions from substrate to thin film has been described in a companion paper (J Am Ceram Soc. 2018;101:1516). Using the same samples as (J Am Ceram Soc. 2018;101:1516), we focus here on later interactions, when the layer is consumed by the substrate resulting from diffusive interactions. Using Secondary Ion Mass Spectroscopy profilometry, we show that the interdiffusion rate increases with the aluminum doping content of the layer. We show that the alkali uptake of silica layers accelerates diffusive exchanges with the substrate, consistently with a decrease of viscosity of the layer. Diffusion profiles of silicon are well reproduced when solving the diffusion equation for a diffusivity having an exponential dependence with silicon concentration. The diffusivity of aluminum is shown to be 10 times slower than the diffusion of silicon. Specific exchanges of the two network formers with network modifiers are deduced from the composition‐space trajectories, providing evidence for multicomponent diffusive couplings between species.

Obtaining large surfaces covered by submicron structures is a challenge in patterning coatings. Using laser induced dewetting, large surface self-assembled ordered metallic structures were used to modify optical properties of interference coatings.