The elastic potential energy of a thin foil deformed by an in-plane 60° dislocation

Abstract

An explicit expression of the elastic potential energy, W ^p, stored in a thin foil by a dissociated dislocation running parallel to the free surfaces is obtained in isotropic elasticity. It is used to discuss the metastable elastic equilibrium of a 60° dislocation in an ultrathin silicon foil when the fault plane is slightly inclined with respect to the free surfaces. The energy W ^p depends in particular on the positions of the two partials in the foil and on the thickness h, a situation not fully considered previously. For such ultrathin foils, propitious to the observation of partial dislocations cores at near atomic resolution, the theory predicts rapid changes with h of the separation distance S. This result is in accordance with previous experimental observations of S realized with the so-called “forbidden-reflection lattice imaging” technique.

Notes

Notes

Interested readers will receive a copy by e-mail of the formulae presented in the appendices.

Two typographical errors should be corrected inside the curly brackets of equation (12) of Youssef and Bonnet 18: (i) the last small parenthesis of the second line should be deleted and (ii) two extra parentheses should be added at the end of the third line.