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Shear-melting of a hexagonal columnar crystal by proliferation of dislocations

L. Ramos·F. Molino
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Abstract

A hexagonal columnar crystal undergoes a shear-melting transition above a critical shear rate or stress. We combine the analysis of the shear-thinning regime below the melting with that of synchrotron X-ray scattering data under shear and propose the melting to be due to a proliferation of dislocations, whose density is determined by both techniques to vary as a power law of the shear rate with a 2/3 exponent, as expected for a creep model of crystalline solids. Moreover, our data suggest the existence under shear of a line hexatic phase, between the columnar crystal and the liquid phase.

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L. Ramos, F. Molino. 2004-07-01. Shear-melting of a hexagonal columnar crystal by proliferation of dislocations. https://doi.org/10.1103/physrevlett.92.018301

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