2. Deformation mechanisms

2.1 Perfect crystal elasticity

A perfect single crystal is a triply periodic stack of atoms, vibrating around their equilibrium position due to thermal activation. The response of such a system to a sufficiently small mechanical excitation corresponds to perfect elastic behavior, linear or not, but always reversible and non-dissipative (§ 2.2 ).

In a perfect crystal, the atoms form a three-dimensional periodic lattice and vibrate around their equilibrium position due to thermal...