Superconductors are classified into two types, called Type I and Type II, based on
their diamagnetic properties. In Type I superconductors, as the applied magnetic
field B increases, so does the opposing magnetizationMuntil the field reaches the critical
field Bc, whereupon the superconductivity disappears. At that point, the perfect
diamagnetic behavior, the Meissner effect, is lost, as illustrated in Figure 8.49.