Experimental Evidence for the Development of Bimodal Grain Size Distributions by the Nucleation-Limited Coarsening Mechanism
Abstract:It has recently been hypothesized that transient bimodal grain size distributions can arise from unimodal distributions during coarsening if the continued growth of a majority fraction of the crystals is arrested by the energy barrier to nucleate new layers. To test this hypothesis experimentally, SrTiO3 has been coarsened in a titania-rich liquid at 1500°C. Measurements of the grain size distribution as a function of time show a transient bimodal distribution that consists of a constant number of larger grains growing many times faster than a decreasing number of much smaller grains. The observations are consistent with the nucleation-limited coarsening theory, which provides a plausible explanation for the development of transient bimodal grain size distributions in systems of crystals bounded by singular surfaces.
Document Type: Research Article
Affiliations: Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213-3890
Publication date: 2007-01-01