Why can moving magnetic fluxoids make a superconductor heat up and lose its superconductivity?

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Figure 1: Specific heat in the normal (Cen) and superconducting (Ces) states of a classic superconductor as a function of absolute temperature. The two functions are identical at the transition temperature (Tc) and above Tc. — superconductivity Figure 1: Specific heat in the normal (C_en) and superconducting (C_es) states of a classic superconductor as a function of absolute temperature. The two functions are identical at the transition temperature (T_c) and above T_c.

In type II superconductors, magnetic fields penetrate the material in the form of quantized fluxoids. When an external electric current is applied, it exerts a force on these fluxoids, causing them to move through the material.1

This motion of fluxoids creates energy dissipation, which generates heat within the superconductor. If the current is sufficiently high, the resulting heat can raise the temperature of the material enough to drive it out of its superconducting state and into a normal, resistive state. To prevent this, manufacturers of superconducting wires often introduce inhomogeneities into the material's composition to "pin" the fluxoids in place, thereby preventing their motion and maintaining the critical current density required for stable operation.1