The results on measuring the I--V characteristics of the metal-semiconductor transition within the Ti (200 nm)|Si@O@Al (180 nm)|Ti (203 nm) test structure are presented. The basis of the Si@O@Al nanocomposite is a solid solution of Al in amorphous silicon a-Si(Al). The I--V of the test structure has a form characteristic of a reverse-biased ohmic contact between a metal and a p-type semiconductor, which implies that a-Si(Al) is a substitutional solid solution. It is shown that the I--V fits well the framework of the metal-semiconductor transition model and the varistor effect of the nanocomposite. Within the framework of the percolation model, it is shown that the I--V give values of the Si@O@Al resistivity, which are overestimated with respect to the resistance of the a-Si(Al) solid solution. Keywords: nanocomposite, amorphous silicon, solid solution, Schottky barrier, nonlinear conductor, dangling bonds.