Structural study of amorphous Pd_(41)Ni_(41)Si_(18) alloy associated with structural relaxation by anomalous X-ray scattering

摘要

Since the amorphous state is not thermodynamically stable, it is known that this state easily transfers to a more stable state when annealed at temperatures sufficiently low that crystallization does not occur. This transfer process has now been interpreted in terms of structural relaxation. The structural relaxa-tion is frequently described by two categories of a topological short-range ordering (TSRO) process and a chemical short-range ordering (CSRO) process [1]. The TSRO process involves irreversible structural change via highly collective atomic rearrangements with the annihilation of density fluctuation and stress relief in the as-quenched specimen [2,3]. On the other hand, the anneal-induced reversible relaxation behaviour is also well documented in some amor-phous alloys [4] and it is considered to be the atomic rearrangement between specific constituent elements. Such reversible relaxation behaviour in amorphous alloys is mainly attributed to the CSRO process [5].