Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 44: Topical Session: TEM-Symposium - In-Situ II

MM 44.4: Vortrag

Mittwoch, 13. März 2013, 17:30–17:45, H25

Electron-beam-stimulated mechanical engineering of nanoscaled amorphous silica — •Mirza Mackovic and Erdmann Spiecker — Center for Nanoanalysis and Electron Microscopy, Cauerstr. 6, 91058 Erlangen, Germany

Oxide glasses are widely used as structural and functional materials in electronic, optical, and nanoelectromechanical devices. Since amorphous silica does not show ductility at room temperature, complications arise if one considers its application in functional devices, because no shaping or re-shaping is possible without significantly rising the temperature. However, using electron-beam-assisted deformation just recently it has been demonstrated that enormous ductility and superplasticity can be achieved for nanoscaled amorphous silica, at or near room temperature [1]. This material behavior is related to the electron-beam-induced generation of structural and bonding defects, facilitating bond-switching events in the silica network and accommodating viscous flow. Using in-situ nanomechanical testing in a transmission electron microscope, we show that this electron-beam-stimulated viscous flow and shape change of nanoscaled silica is even reversible and can thus be considered for re-shaping not only once, but multiple times. Furthermore, we demonstrate that this phenomenological reversibility can be exploited for generating anisotropic glass topology by specific electron-beam-stimulated quenching under mechanical load. This offers new opportunities for fundamental studies on structure-property relations of nanoscaled glass, which have remained unexplored till now. [1] K. Zheng et al., Nature Comm. 1:24, DOI: 10.1038/ncomms1021.