Muon-spin-rotation measurements of the penetration depth in Li₂Pd₃B

الأصل · EN

Measurements of the magnetic field penetration depth λ in the ternary boride superconductor Li₂Pd₃B (Tc≃7.3 K) have been carried out by means of muon-spin rotation (μSR). The absolute values of λ, the Ginzburg-Landau parameter κ, and the first Hc₁ and the second Hc₂ critical fields at T=0 obtained from μSR were found to be λ(0)=252(2) nm, κ(0)=27(1), μ₀Hc₁(0)=9.5(1) mT, and μ₀Hc₂(0)=3.66(8) T, respectively. The zero-temperature value of the superconducting gap Δ₀=1.31(3) meV was found, corresponding to the ratio 2Δ₀/kBTc=4.0(1). At low temperatures λ(T) saturates and becomes constant below T≃ 0.2Tc, in agreement with what is expected for s-wave BCS superconductors. Our results suggest that Li₂Pd₃B is a s-wave BCS superconductor with the only one isotropic energy gap.