MEISSNER EFFECT
When magnetic field is applied to a super conductor at T < ๐๐
then magnetic lines of force does not passes through it and behaves as a perfect diamagnetic material. This effect is first observed by Meissner and familiarized as Meissner effect.
We know B = ยตo (H + M)
In superconducting state, the magnetic lines are not passing through it. So B = 0
0 = ยตo (H + M)
H = - M
๐ = ๐ = −1
๐ป
The above expression indicates that, only diamagnetic materials can show negative
susceptibility. It concludes that, when weak magnetic field (H < Hc) is applied to a
superconductor then the magnetic lines of force does not penetrate through it and shows
perfect diamagnetic property. This property is called as Meissner effect.