Surface impedance measurements on Nb${}_3$Sn at high magnetic fields

Abstract

Nb${}_3$Sn is a superconductor of great relevance for perspective RF applications. We present for the first time surface impedance $Z_s$ measurements at 15 GHz and low RF field amplitude on Nb${}_3$Sn in high magnetic fields up to 12 T, with the aim of increasing the knowledge of Nb${}_3$Sn behavior in such conditions. $Z_s$ is a fundamental material parameter that directly gives useful information about the dissipative and reactive phenomena when the superconductor is subjected to high-frequency excitations. Therefore, we present an analysis of the measured $Z_s$ with the aim of extracting interesting data about pinning in Nb${}_3$Sn at high frequencies. From $Z_s$ we extract the vortex motion complex resistivity to obtain the $r$-parameter and the depinning frequency ${\nu }_p$ in high magnetic fields. The comparison of the results with the literature shows that the measured ${\nu }_p$ on bulk Nb${}_3$Sn is several times greater than that of pure Nb. This demonstrates how Nb${}_3$Sn can be a good candidate for RF technological applications, also in high magnetic fields.

ASC 2018 conference, accepted in IEEE Trans Appl Supercond

References in corpus (6)

• A Review of the Properties of Nb3Sn and Their Variation with A15 Composition, Morphology and Strain State
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Cited by in corpus (1)

• Measurements of microwave vortex response in dc magnetic fields in Tl${}_2$Ba${}_2$CaCu${}_2$O${}_{8+x}$ films