Abstract
S. Sengupta: „How elastic is an elastic solid? Droplet fluctuations, plasticity and microstructure selection in solids”
Centre for Advanced Materials, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India
Beginning with our early attempts to obtain elastic constants of an ideal crystal from fluctuations of the local strain, we show that the local elastic behavior of an ideal solid is actually rather complex. The measured strain correlation functions behave quite differently from what is expected from a perfect elastic continuum without defects. We show that at any density there are randomly generated regions - so called non-affine zones (NAZs) - which cannot be obtained by an affine transformation of a reference crystal. The density of NAZs increase as the solid-liquid boundary is approached and we identify NAZs with droplet fluctuations of the metastable liquid within a solid. We attempt to connect the existence of these NAZs and their dynamics with several phenomena in solids notably solid plasticity and the selection of microstructure in a solid undergoing structural transitions.