Magnetocaloric effect in type-II mesoscopic superconductors

The isothermal evolution of a type-II mesoscopic superconducting cylinder under a magnetic field expansion is analyzed through the standard time-dependent Ginzburg-Landau theory. We calculate the isothermal variation of the entropy, ΔS(T,H), by means of Maxwell's relation to show that it reaches a maximum at a temperature T near and below the critical temperature Tc(H). We show how vortex configurations affect this process, which is the building block of the magnetocaloric effect. The conclusion is that in all situations heat is always absorbed from the environment, qualifying the mesoscopic superconductor as a magnetic refrigerator.