Two-gap superconductivity seen in penetration-depth measurements of Lu2Fe3Si5 single crystals

TitleTwo-gap superconductivity seen in penetration-depth measurements of Lu2Fe3Si5 single crystals
Publication TypeJournal Article
Year of Publication2008
AuthorsGordon RT, Vannette MD, Martin C, Nakajima Y, Tamegai T, Prozorov R
Journal TitlePhysical Review B
Volume78
Pages024514
Date PublishedJul
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000258190200114
KeywordsEARTH-IRON SILICIDES, field, heat, SC2FE3SI5
Abstract

A single crystal of superconducting Lu2Fe3Si5 was studied using the tunnel-diode resonator technique in the Meissner and mixed states. The temperature dependence of the superfluid density provides strong evidence for two-gap superconductivity and indicates that there are nearly equal contributions from each gap having magnitudes of Delta(1)/k(B)T(c)=1.86 and Delta(2)/k(B)T(c)=0.54. In the vortex state, the pinning strength shows unusually strong temperature dependence and is nonmonotonic with the magnetic field (peak effect). The irreversibility line is sharply defined and quite distant from the H-c2(T) line, which hints at enhanced vortex fluctuations in this two-gap system. Altogether, our findings from electromagnetic measurements provide strong support for the existence of two-gap superconductivity in Lu2Fe3Si5, as previously suggested from specific-heat measurements.

DOI10.1103/PhysRevB.78.024514
Alternate JournalPhys. Rev. B