Depending upon their behavior in an external magnetic field, superconductors are divided into two types:

a) Type I superconductors and b) Type II superconductors

Let us discuss them one by one:

1) Type I superconductors:

a). Type I superconductors are those superconductors which loose their superconductivity very easily or abruptly when placed in the external magnetic field. As you can see from the graph of intensity of magnetization (M) versus applied magnetic field (H), when the Type I superconductor is placed in the magnetic field, it suddenly or easily looses its superconductivity at critical magnetic field (Hc) (point A).

After Hc, the Type I superconductor will become conductor.

b). Type I superconductors are also known as soft superconductors because of this reason that is they loose their superconductivity easily.

c) Type I superconductors perfectly obey Meissner effect.

d) Example of Type I superconductors: Aluminum (Hc = 0.0105 Tesla), Zinc (Hc = 0.0054)

2) Type II superconductors: More >