Magnetic measurement of the critical current anisotropy in coated conductors

TL;DR

This paper presents a method to measure the critical current anisotropy in coated conductors using magnetization hysteresis loops, improving resolution and avoiding complex sample preparation.

Contribution

It introduces a technique to accurately determine critical current anisotropy from magnetization data, eliminating spurious signals and matching transport measurements.

Findings

Method effectively measures anisotropy at high currents.

Measurement resolution is significantly improved.

Results agree with transport data.

Abstract

We determine the critical current anisotropy at maximum Lorentz force from hysteresis loops in a vibrating sample magnetometer. To eliminate the signal of spurious variable Lorentz force currents it is sufficient to cut the sample to a specific length, which is calculated from the position dependent sensitivity of the instrument. The procedure increases the resolution of the measurement and the results compare well to transport data on the same sample. As the electric field in magnetisation measurements is lower than in transport experiments the anisotropy at high currents (low temperatures and fields) can be measured without the need of making current contacts or any special sample preparation.