Question

The superconducting transition temperature in a metal is 4.2 K for zero magnetic field. If the magnetic field required to destroy superconductivity at 3.2 K is 0.02T, calculate the critical magnetic field at absolute zero.

Answer 1

Calculate the critical magnetic field by the relation as follows:

B_c (T)=B_c (0) 〖[1-T/Tc]〗^2

Here T is the temperature and Tc is the ritical temperature .

0.2 T=B_c (0) 〖[1-3.2/4.2]〗^2

0.02 T = B_c (0)(0.056)

B_c (0)=0.357