Composite microhardness of quartz-Al structures

The microhardness-depth profiles of as-obtained and annealed quartz (substr ate)-Al (film) structures have been investigated. A layer of constant hardn ess has been detected beneath the initial interface. This is supposed to re sult from incorporation of aluminium atoms into the surface layer of the su bstrate, reduction of SiO2 and diffusion of the atoms of a certain element during the processes of preparing and rapid thermal annealing of the struct ures.