A generalized phenomenological model for the magnetic field penetration and magnetization hysteresis loops of a type-II superconductor

TL;DR

This paper introduces a comprehensive phenomenological model that accurately simulates magnetic field penetration and hysteresis loops in type-II superconductors, accounting for surface and bulk effects.

Contribution

The model uniquely combines surface screening and bulk pinning effects in a self-consistent manner, applicable across various superconductor types and kappa values.

Findings

Model fits experimental data well

Parameters can be extracted from fits

Applicable to different type-II superconductors

Abstract

A generalized phenomenological model for the critical state of type-II superconductors with magnetic field parallel to the superconducting plate is proposed. This model considers the global magnetization including both the equilibrium magnetization from surface screening current and the non-equilibrium magnetization from bulk pinning in a self-consistent way. Our model can be used to simulate the magnetization-hysteresis-loops (MHLs) and flux penetrating process of different type-II superconductors, from low- to high-kappa values. Here we take an optimally doped Ba0.6K0.4Fe2As2 single crystal as a testing example. The model can fit the data quite well and several important parameters can be extracted from the fitting. Thus, the model can be extended to a general case for studying the magnetization and flux penetration in other type-II superconductors.