Magnetic susceptibility of the normal-superconducting transition in high-purity single-crystal alpha-uranium

TL;DR

This study uses advanced microfabricated magnetometers to detect and analyze the superconducting transition in high-purity alpha-uranium, revealing filamentary superconductivity at around 0.7 K.

Contribution

First application of microfabricated coplanar magnetometers to measure superconductivity in alpha-uranium, demonstrating their high sensitivity and potential for high-field studies.

Findings

Superconductivity onset at ~0.7 K confirmed by susceptibility and resistivity.

Superconducting volume fraction suggests filamentary nature.

Micro-magnetometers are effective in high magnetic fields exceeding 100 T.

Abstract

We report complex ac magnetic susceptibility measurements of a superconducting transition in very high-quality single-crystal alpha-uranium using microfabricated coplanar magnetometers. We identify an onset of superconductivity at T~0.7 K in both the real and imaginary components of the susceptibility which is confirmed by resistivity data. A superconducting volume fraction argument, based on a comparison with a calibration YBCO sample, indicates that the superconductivity in these samples may be filamentary. Our data also demonstrate the sensitivity of the coplanar micro-magnetometers, which are ideally suited to measurements in pulsed magnetic fields exceeding 100 T.