High quality MgB2 thin films in-situ grown by dc magnetron sputtering

TL;DR

This paper reports the successful in-situ growth of high-quality MgB2 superconducting thin films using dc magnetron sputtering, achieving properties comparable to single crystals and demonstrating scalability.

Contribution

It introduces a scalable in-situ sputtering method for producing high-quality MgB2 thin films with excellent superconducting properties.

Findings

Maximum Tc of 35 K achieved

Residual resistivity ratio up to 1.6

Critical current density > 1 MA/cm2

Abstract

Thin films of the recently discovered magnesium diboride (MgB2) intermetalic superconducting compound have been grown using a magnetron sputtering deposition technique followed by in-situ annealing at 830 C. High quality films were obtained on both sapphire and MgO substrates. The best films showed maximum Tc = 35 K (onset), a transition width of 0.5 K, a residual resistivity ratio up to 1.6, a low temperature critical current density Jc > 1 MA/cm2 and anisotropic critical field with gamma = 2.5 close to the values obtained for single crystals. The preparation technique can be easily scaled to produce large area in-situ films.