Azimuthal orientational correlations due to excluded volume epitaxy in growing anisotropic grains |
| |
Authors: | S.P. Gido |
| |
Affiliation: | Polymer Science and Engineering Department , University of Massachusetts Amherst , Amherst, MA 01003, USA |
| |
Abstract: | The microstructure of anisotropically shaped grains can strongly influence a range of material properties, including transport, mechanical and electro-optical. A grain-structure-related phenomenon, known as excluded volume epitaxy (EVE), is reported in this study. EVE is a local, inter-grain orientational correlations effect, which results from a combination of continuous nucleation of anisotropic grains and impingement of growing grains. Due to EVE, anisotropically shaped grains have a tendency to be similarly aligned in a local neighbourhood, despite the absence of any forced global orientation in the sample. The effect has been repeatedly observed by the authors in block copolymers, as illustrated by a representative TEM image. Optical microscopy of anisotropically shaped non-polymeric crystals revealed the generality of this effect. The simulation study revealed a tendency for azimuthal, inter-grain orientational correlation and re-confirmed the experimental observation of EVE. |
| |
Keywords: | azimuthal orientational correlations anisotropic grains block copolymer microstructure transmission electron microscopy (TEM) grain growth |
|
|