Annealing and tempering of glass will change the glass and coating microstructure and cause interdiffusion between layers. SIMS depth profiling shows diffusion of major and minor elements between layers. TEM shows changes in microstructure.
SIMS shows major diffusion of Na after tempering, from the glass substrate through all of the coating layers and to the surface. Si and N have diffused from the SiAlN layers into the adjoining layers.
TEM shows no change in coating layer thicknesses after tempering. However, the interfaces between layers have become more defined and one interfacial layer has disappeared.