I used the fit function χ=χ0 + C/(T-θ), χ0 =χdia +χPauli = temperature independent contribution.
Taking χ0 into account, I only ploted the susceptibility vs. temperature curve. The temperature range selected for fitting is above the superconducting critical temperature, such as from 50K to 140K...
I am confused about the magnetic susceptibility vs. temperature curves (or MT) of superconductors (SCs).
In the normal conduction state (I measured from 4.5K to 300K), the susceptibility curve can obey the Curie-Weiss law. But when I fitted the data via the Curie-Weiss law in a different...