Relaxation and crystallization processes in partially or completely amorphized metallic systems: An ion bombardment study on In_2Au

摘要

Polycrystalline In_2Au films prepared by evaporation were bombarded at 4.2 K as well as 80 K with 300 keV Ar~+ ions. In this way, the crystalline phase can be transformed stepwise into an amorphous phase, and by in situ controlling the electrical resistance of the films, samples containing well-defined volume fractions of the amorphous phase can be prepared. Performing isothermal temporal relaxation experiments after switching off the ion beam on such samples as well as annealing cycles determining their crystallization temperature T_x, the question could be addressed as to the effect of crystalline nuclei on these properties. A monotonic decrease of T_x is found for an increasing volume fraction of the crystalline phase. The temporal relaxation exhibits a stretched exponential behavior with an exponent pointing to an effective dimension of d = 3.