Dr. Hans Fecht

Abstract:

So-called “nanoglasses” are considered as non-crystalline solids which exhibit a glass-like atomic structure and contain a considerable number of internal interfaces. This metastable state of matter can be synthesized by RF magnetron thin film sputter deposition as an alternative to other methods including inert gas condensation and chemical decomposition on a nanoscale. Using sputtering targets of VIT105 and Au-based BMG as well as Fe-Sc the resulting nanostructures can be varied from monolithic amorphous to nanoglass and to columnar amorphous nanostructures at varying Argon base pressure. Remarkably, the BMG based nanoglass specimen clearly exhibit an anomaly of the specific heat typical for the glassy state. While generally glassy structures lack ductility, the nanoglass state exhibits superior mechanical properties achieving a remarkable level of plastic deformation in nanoindentation experiments. Further details, also in relation to a recent theoretical approach as well as measurements of electrical and magnetic properties will be presented and discussed.