ABSTRACT
The structure shown in the magnetic eld intensity for vanadium in Figure 12.1 is not known in type I superconductors. It is a consequence of the vortex lattice structure in vanadium as a type II superconductor. The second-order phase transition that leads to the formation of the vortex lattice appears as a result of a thermodynamic instability associated with the negative surface energy at sufciently high magnetic eld strengths in superconductors [6,7].
