Oscillating Behavior of Chemical and Structural Characteristics of Alloys at Hydrogenation

Abstract

This work aims provide an experimental overview of results revealing a unique phenomenon such as non-stochastic changes of the local composition and ordering of the metal-elements within alloys. A necessary and sufficient condition for the occurrence of this phenomenon is the charging with hydrogen the structure of the materials. Interestingly the element distribution changes are observed at room temperature and after a rather long rest time from the initial hydrogen insertion. The changes of positions and environments of the elements yield changes in phase compositions. This effect was observed in both amorphous and crystallized compounds, here we will report on the first category of materials, in particular Finemet alloys. The phenomenon was investigated using various experimental techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM).