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arXiv · 1709.02668

Triple junction at the triple point resolved on the individual particle level

M. Chaudhuri·E. Allahyarov·H. Löwen·S. U. Egelhaaf·D. A. Weitz
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Abstract

At the triple point of a repulsive screened Coulomb system, a face-centered-cubic (fcc) crystal, a body-centered-cubic (bcc) crystal and a fluid phase coexist. At their intersection, these three phases form a liquid groove, the triple junction. Using confocal microscopy, we resolve the triple junction on a single particle level in a model system of charged PMMA colloids in a nonpolar solvent. The groove is found to be extremely deep and the incommensurate solid-solid interface to be very broad. Thermal fluctuations hence appear to dominate the solid-solid interface. This indicates a very low interfacial energy. The fcc-bcc interfacial energy is quantitatively determined based on Young's equation and, indeed, it is only about 1.3 times higher than the fcc-fluid interfacial energy close to the triple point.

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M. Chaudhuri, E. Allahyarov, H. Löwen, S. U. Egelhaaf, D. A. Weitz. 2017-09-08. Triple junction at the triple point resolved on the individual particle level. https://doi.org/10.1103/physrevlett.119.128001

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