Berlin 2008 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 23: Poster session
MM 23.28: Poster
Dienstag, 26. Februar 2008, 14:45–18:00, Poster B
Pd81Si19-Metallic Nanoglasses with Enhanced Excess Volume — •Yue Zhang, Horst Hahn, and Herbert Gleiter — Institute of Nanotechnology, Forschungszentrum Karlsruhe, Germany
Pd81Si19 metallic nanoglasses were synthesized by inert gas condensation and in situ compaction. In this technique, amorphous nanoparticles, prepared by evaporation in an inert gas atmosphere, are collected and subsequently compacted using uniaxial pressures. During the compaction, surfaces are converted into internal interfaces and additional free volume is introduced into the amorphous structure. Wide angle X-ray diffraction and high resolution electron microscopy are employed to characterize the atomic structure. The excess volume fraction was calculated using classical free-volume theory from differential calorimetric scanning data. In order to have a comparison, glassy ribbons and bulk metallic glass rods with the same chemical composition were prepared using melt-spinning and B2O3 flux casting techniques, respectively. Comparing with these conventional metallic glasses, the Pd81Si19 nanoglasses exhibit an enhanced excess volume, resulting in modified properties.