Juergen Eckert

Abstract:

The structure of glasses is generally taken to be isoconfigurational, although it is well-known that the details of structure arrangement strongly depend on the temperature-time history experienced when establishing the glassy state. Recent studies of glass-forming metallic systems have revealed intriguing complexity, e.g. unusual shifts in radial distribution functions with temperature change or upon mechanical loading in the elastic or plastic regime. Nearest neighbour distances and medium-range order structural arrangements appear to change, e.g. shorten upon heating or become larger with decreasing temperature. Concomitantly, temperature changes as well as static or dynamic mechanical loading within the nominally elastic regime can trigger significant changes in glass properties, which are directly correlated with local non-reversible configurational changes due to non-affine elastic or anelastic displacements. All these findings strongly suggest that the characteristics of the atomic structure decisively determine the properties of the glass. Recent findings and developments along these lines will be summarized, and results from high-energy synchrotron x-ray radiation investigations at different temperatures, and after mechanical loading, will be related to the atomic structure of the material and its dependence on temperature, mechanical load, as well as intrinsic heterogeneities and length-scale modulation, such as to elucidate the correlation between atomic arrangement and mechanical properties.