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M: Metallphysik

M 7: Glasdynamik

M 7.5: Vortrag

Montag, 8. März 2004, 15:45–16:00, H16

Mechanisms of ion irradiation-induced viscous flow in glasses: the role of point defects — •S.G. Mayr — I. Physikalisches Institut, Georg-August-Universität Göttingen, Tammannstr. 1, 37077 Göttingen

The nature of ion irradiation-induced viscous flow in amorphous solids is inverstigated using experiments and molecular dynamics computer simulations. Experimentally, relaxation of film stresses and smoothing of rough surfaces illustrate, that many amorphous solids undergo Newtonian flow far below their respective glass temperature during ion bombardement [1]. Using molecular dynamics computer simulations we study the atomic-scale mechanisms governing radiation-induced viscous flow under conditions, where local melting along the ion tracks is not dominant. We show, that injection of interstitial- and vacancy-like defects induces the same amount of flow as recoil events, indicating, that point-defect-like entities in the amorphous matrix act as local shear instabilities and mediate viscous flow [2].
Financially supported by the DFG - SFB 602, TP B3
S.G. Mayr and R.S. Averback, Phys. Rev. Lett. 87 (2001), 196106
S.G. Mayr, Y. Ashkenazy, K. Albe and R.S. Averback, Phys. Rev. Lett. 90 (2003), 55505