Phase Segregation and Coherent Scattering

Materials Science Research Group

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Overview

Phase separation and phase ordering are common ways to produce materials with a complicated multiphase structure. A typical example is the ``quenching'' of a melt or a white-hot solid by throwing it into a bucket of water. This method has been used by blacksmiths since time immemorial to improve the materials properties of solids, and it is still used to produce high-tech alloys and glasses. During the phase-segregation process the material contains a high density of interfaces and other defects, which move as the phase morphology evolves.

One of the most common ways to obtain information about the evolving phase morphology is scattering of radiation, such as photons (X-rays or light), neutrons, or electrons. The intensity of the scattered radiation at a particular wave vector is proportional to the squared Fourier transform of the phase morphology. In this project we study how the statistical fluctuations in the scattering intensity provides information about the local structure and dynamics of the moving interfaces in materials during the phase segregaion following a temperature quench. The work is a collaboration of G. Brown and P.A. Rikvold with Professors Martin Grant and Mark Sutton at McGill University in Montreal.

Papers

To the right are links to images, animations, and other resources which are intended to augment the following papers.

4. cond-mat/9905343

Title: Evolution of speckle during spinodal decomposition
Authors: Gregory Brown (McGill & Florida State), Per Arne Rikvold (Florida State), Mark Sutton (McGill), Martin Grant (McGill)

3. cond-mat/9805360

Title: Universality and Scaling for the Structure Factor in Dynamic Order-Disorder Transitions
Authors: Gregory Brown, Per Arne Rikvold (Florida State Univ), Martin Grant (McGill Univ)

2. cond-mat/9606151

Title: Numerical simulations of scattering speckle from phase ordering systems
Authors: Gregory Brown, Per Arne Rikvold, Martin Grant

1. cond-mat/9706140

Title: Speckle from phase ordering systems
Authors: Gregory Brown, Per Arne Rikvold, Mark Sutton, Martin Grant (Florida State, McGill, Kyoto)

Additional Resources

Note: MPEG files may not work in all viewers on all platforms. We apologize for any inconvenience this may cause you.

Image of Phase Segregation (70 Kb)

Image of Scattering Intensity During Phase Segregation (47 Kb)

PDF of APS March Meeting 200, Two-time Correlations and Coherent Scattering Experiments on Phase-segregating materials (0.3 Mb)