INFLUENCE OF CRYSTALLIZATION PARAMETERS ON THE FORMATION OF HIGHLY NONEQUILIBRIUM STATES IN IMMISCIBLE SYSTEMS

Data are presented on the improved ion-plasma sputtering from composit e targets of the binary systems W-(Ba, Ag, Cu). The deposited films ar e mixed amorphous-crystalline or fully amorphous. The amorphous phases decompose by precipitation of equilibrium components. By applying an additional highly efficient ion-accelerating device, the amorphous sta te can be obtained even in pure W-films deposited on substrates near r oom temperature. From molecular-kinetic theory an analysis has been ma de of the influence of thermodynamic (entropy change on condensation) and kinetic (atomic length parameter) factors influencing the amorphiz ation by vapour deposition of systems for which the components show in complete miscibility even in liquid state. The model presented is in r easonable agreement with experimental data on the formation of metasta ble (including amorphous) states. Direct correlations are established between the positive heat of formation of an alloy, its tendency to be come amorphous and the effective value of an atomic length parameter. The succession of crystallization of components from the amorphous sta te can also be predicted.