Current percolation and anisotropy in polycrystalline MgB$_2$

TL;DR

This paper investigates how anisotropy affects the transport current in polycrystalline MgB₂, proposing a model based on anisotropic London theory, grain boundary pinning, and percolation theory, which aligns well with experimental data.

Contribution

It introduces a novel model for critical current density in MgB₂ that incorporates anisotropic effects and percolation theory, validated by experimental agreement.

Findings

Calculated currents match experimental data

Anisotropy parameters agree with theoretical predictions

Model effectively describes transport in MgB₂

Abstract

The influence of anisotropy on the transport current in MgB$_2$ polycrystalline bulk samples and wires is discussed. A model for the critical current density is proposed, which is based on anisotropic London theory, grain boundary pinning and percolation theory. The calculated currents agree convincingly with experimental data and the fit parameters, especially the anisotropy, obtained from percolation theory agree with experiment or theoretical predictions.