Structural relaxation in a Fe-based metallic glass: Changes in local structure and role of heterogeneity

Atomic structure evolution induced by thermal relaxation is investigated in Fe80P11C9 metallic glass by a suite of techniques. The topological structure of Fe80P11C9 metallic glasses characterized by the Voronoi polyhedrons varies with relaxation proceeding. Meanwhile, the results of partial pair distribution functions and local composition distribution indicate that the degree of the chemical order for different species changes and the solvent-solute correlation significantly enhances. Moreover, the Mössbauer spectra measurements suggest that significant element redistribution occurs during the structural relaxation. Hence, only topological structure change is insufficient to describe the structural relaxation. These results manifest that the structural relaxation can be described via heterogeneity degeneration, which is also supported by the small angle X-ray scattering measurements.