Nanoglasses – news from the amorphous state
Nanoglasses, in contrast to homogeneous metallic glasses, are constituted of two distinctly different amorphous components, one resembling the atomic structure of rapidly quenched glasses, one with a distinctively different, but well-defined, structure present in the interfacial regions. Such nanostructured glasses can be prepared by a variety of experimental routes: (1) mechanical compaction of amorphous nanoparticles with sizes in the range of 5-10 nm; (2) thin film deposition; (3) melt casting of alloys with special compositions; (4) energetic impact of small clusters. The differences in the atomic structure of nanoglasses result in drastic changes of the mechanical and magnetic properties, to biocompatibility.
The talk will summarize the current knowledge on nanoglasses, which are prepared by route (1) and (4), emphasizing the differences of the atomic structure and the consequences on the mechanical and magnetic properties. The interfacial component is found to be structurally different from rapidly quenched glasses (RQ) and is characterized by an increased free volume, presence of medium range order, and typically combined with large differences in the chemical composition.