Fabrication of superconducting MgB2 thin films by magnetron co-sputtering on (001) MgO substrates

TL;DR

This study reports the fabrication of superconducting MgB2 thin films on MgO substrates using magnetron co-sputtering, highlighting the importance of substrate and annealing temperatures in achieving superconductivity with a critical temperature of 27.1K.

Contribution

It introduces a co-sputtering method for MgB2 film fabrication and identifies optimal temperature conditions for superconductivity.

Findings

Achieved a critical temperature of 27.1K.

Substrate and annealing temperatures are crucial for film quality.

Crystalline structure confirmed by x-ray diffraction.

Abstract

We fabricated superconducting MgB2 thin films on (001) MgO substrates. The samples were prepared by magnetron rf and dc co-sputtering on heated substrates. They were annealed ex-situ for one hour at temperatures between 450{\deg}C and 750{\deg}C. We will show that the substrate temperature during the sputtering process and the post annealing temperatures play a crucial role in forming MgB2 superconducting thin films. We achieved a critical onset temperature of 27.1K for a film thickness of 30nm. The crystal structures were measured by x-ray diffraction.