A NON CONVENTIONAL THERMODYNAMICAL MODEL FOR NANOCRYSTALS WITH DEFECTS OF DISLOCATION

In the framework of the extended irreversible thermodynamics a non conventional description for nanocrystals with defects of dislocation is given, introducing a second order dislocation tensor a la Maruszewski, its gradient and its fux as internal variables in the thermodynamic state vector. Liu's theorem is used to analyze the entropy inequality and to derive the laws of state, the affinities, the entropy fux and the residual inequality. To close the system of equations illustrating the behaviour of the media under consideration, the constitutive equations and the rate equations for the dislocation fi eld, its fux and the heat fux, presenting a relaxation time and describing disturbances propagating with infi nite velocity, are derived, in a fi rst approximation. The behaviour of dislocation defects in nanostructures is one of the challenges in the so called "defects engineering", because they have a direct influence on mechanical and transport properties. The obtained results have applications in nanotechnology and several fi elds of applied sciences.