Type I and Type II Superconductors

Whilst chapter four treated superconductors as perfectly diamagnetic a new type of superconductor, type II, is introduced. Rather than expelling all the magnetic field from the material type II superconductors allow magnetic flux to penetrate. The penetration of flux gives rise to screening currents which in turn shield the bulk of the material from the external field. The penetration of the field is also shown to be a quantised effect.