Properties of Shear Transformation Zones in Metallic Glasses

The concept of shear transformations was coined by Argon, based on observations in bubble-raft models of glasses [1]. Later, 3-D observations in colloidal glasses and molecular dynamics simulations confirmed this picture. Because of the disordered structure of glasses, there is no known contrast mechanism for imaging shear transformation zones (STZs). Diffraction techniques provide macroscopic averages and are unlikely to reveal detailed information about STZs. Using anelastic relaxation experiments, we have recently been able to resolve a hierarchy of STZs that differ from each other by a single atom. In this talk, the results will be contrasted to previous reports, and the implications for the understanding of glass behavior will be discussed.