Thermodynamics of Type-II High-Tc Superconductors

In this paper we construct a geometric model for the thermodynamics of a vortex field in type-II high-T-c superconductors, within a nonconventional model based on the extended irreversible thermodynamics with internal variables. For this purpose we derive the transformation induced by the process and the dynamical system for a simple material element of the vortex lattice. Furthermore, we obtain the expression of the entropy function, the necessary conditions for its existence and the entropy 1-form, as a starting point to investigate a thermodynamical phase space and the state laws.