The temperature-dependent surface critical magnetic field (HC3) of magnetic superconductors: Applied to lead bismuth (Pb82Bi18) superconductors

In this research, we investigated the surface critical magnetic field (HC3) of magnetic superconductors by the Ginzburg-Landau (GL) Theory. We used the 1st GL equation to calculated HC3 by variation method analytically and modified to the temperature dependence properties. The analytical formula of surface critical magnetic field depended on magnetic properties of material: susceptibility and differential susceptibility. In addition, the temperature-dependent surface critical magnetic field was studied by four models; Chen's model, Zhu's model, Shanenko's model and Changjan & Udomsamuthirun 's model. Focused on four models, our numerical calculation based on Changjan & Udomsamuthirun's model could find a good agreement with the experimental data of Pb82Bi18 superconductors vicinity the critical temperature scenery.