high-Tc superconductors from isothermal magnetization data. Influence of a temperature dependent Ginzburg-Landau parameter
نویسندگان
چکیده
We show that the scaling procedure, recently proposed for the evaluation of the temperature variation of the normalized upper critical field of type-II superconductors, may easily be modified in order to take into account a possible temperature dependence of the Ginzburg-Landau parameter κ. As an example we consider κ(T ) as it follows from the microscopic theory of superconductivity.
منابع مشابه
Scaling of the Equilibrium Magnetization in the Mixed State of Type-II Superconductors
We discuss the analysis of mixed-state magnetization data of type-II superconductors using a recently developed scaling procedure. It is based on the fact that, if the Ginzburg-Landau parameter κ does not depend on temperature, the magnetic susceptibility χ(H,T ) is a universal function of H/Hc2(T ), leading to a simple relation between magnetizations at different temperatures. Although this sc...
متن کاملThe Average Kinetic Energy of the Superconducting State
Isothermal magnetization curves are plotted as the magnetization times the magnetic induction, 4πM · B, versus the applied field, H. We show here that this new curve is the average kinetic energy of the superconducting state versus the applied field, for type-II superconductors with a high GinzburgLandau parameter κ. The maximum of 4πM · B occurs at a field, H∗, directly related to the upper cr...
متن کاملContinuous Ginzburg–Landau description of layered superconductors
The behaviour of the order parameter and its effects in intrinsically-layered superconductors are studied within a continuous Ginzburg–Landau model. A simple model of interlayer coupling is proposed in which we suggest that the coupling strength between superconducting and insulating layers may be qualitatively described by a reciprocal of a difference between the order parameters at the respec...
متن کاملhigh-Tc superconductors from isothermal magnetization data. Application to polycrystalline samples and ceramics
Using a recently developed scaling procedure that allows to establish the temperature dependence of the normalized upper critical field hc2(T ) = Hc2(T )/Hc2(T0) from measurements of the equilibrium isothermal magnetization, we analyze experimental data obtained on polycrystalline and ceramic samples. We show that the scaling procedure works quite well in all cases that we have considered. This...
متن کاملUpper critical field in dirty two-band superconductors: Breakdown of the anisotropic Ginzburg-Landau theory
We investigate the upper critical field in a dirty two-band superconductor within quasiclassical Usadel equations. The regime of very high anisotropy in the quasi-2D band, relevant for MgB2, is considered. We show that strong disparities in pairing interactions and diffusion constant anisotropies for two bands influence the in-plane Hc2 in a different way at high and low temperatures. This caus...
متن کامل