Cooperatively rearranging regions (CRRs) play a central role in the temperature dependence of glass dynamics. We record real-time atomic resolution movies of individual CRRs, while ramping their temperature. Between 295 and 326 K, well below the bulk glass transition temperature T g, the rate coefficient for two-state hopping of CRRs increases over tenfold, yielding an Arrhenius activation barrier of ≈10k BT g. By time resolving the dynamics of many individual CRRs, we show that highly stretched dynamics of the CRR ensemble results mainly from spatial heterogeneity, less from temporal heterogeneity of individual CRRs.
ASJC Scopus subject areas
- Physics and Astronomy(all)