Magnetization heat in superconductors and in Eddy current problems: a classical thermodynamic approach

In thermodynamics studies, the problem of the work done by magnetized materials is often approached with a general theorical approach. Sometimes, ambiguities can be found in the demonstrations, because some authors do not clearly specify the terms in the relations. Conversely, a definition of "heat of magnetization" is not given in a general complete way. Some engineers and physicists use practical relations to calculate power dissipated on superconducting materials during magnetization cycles, but it is not possible to find theoretical works that justify the validity of these relations in general situations, for example, as instantaneous losses. In this paper, we want to approach both these aspects with a more complete analysis.