Irreversibility temperature in superconductors

[peterjaybee]

Hello, I would be grateful is someone could explain what the irreversibly temperature in type II superconductors is.

I have just done some NMR experiments on MgB2 and get a lineshape change at the the irreversibility temperature as opposed to the field corrected Tc, so I believe it has something to do with the flux lattice formation.

Regards,

Peter

 

[M@2]

Shouldn't You give a reference to yous results?