The Magnetoresistance in Iron-based Superconductors

Abstract

The phase transition of vortex matter from solid to liquid was studied in iron-based superconductors. Based on the traditional vortex glass theory, we have examined the magnetoresistivity data of iron-based superconductors using our extended thermal activation model: ρ(B,T) = ρ((T-T g (B))/(T c (0)-T g (B))) v(z-1) . We predict that the magnetic field-dependent area S + S? which integrates ρ with T is proportional to B β , where β is the vortex glass transition exponent. From our calculation, the vortex glass transition exponent is 0.33, close to the exponent of area S?+ S is 0.31 in SmO 0.9 F 0.1 FeAs; the exponent of area S is 0.63, which is close to the irreversibility line exponent 2/3. Both of the results show the validity of our model. In addition, our model is shown to be effective in describing irreversibility behavior in layered superconductors.