1307.6386 (H. Saadaoui et al.)

μSR and NMR study of the superconducting Heusler compound YPd2Sn    [PDF]

H. Saadaoui, T. Shiroka, A. Amato, C. Baines, H. Luetkens, E. Pomjakushina, V. Pomjakushin, J. Mesot, M. Pikulski, E. Morenzoni

We report on muon spin rotation/relaxation and $^{119}$Sn nuclear magnetic resonance (NMR) measurements to study the microscopic superconducting and magnetic properties of the Heusler compound with the highest superconducting transition temperature, YPd2Sn ($T_c=5.4$ K). Measurements in the vortex state provide the temperature dependence of the magnetic penetration depth $\lambda(T)$ and the field dependence of the superconducting gap $\Delta(0)$. The results are consistent with a very dirty s-wave BCS superconductor with a gap $\Delta(0)=0.85(3)$ meV, magnetic penetration depth, $\lambda(0)= 212(1)$ nm, and a Ginzburg-Landau coherence length $\xi_{GL}(0)\cong 23$ nm. The muSR data in a broad range of applied fields are consistently reproduced by assuming a field-dependent effective superconducting gap, with a similar dependence on field as the critical temperature. In spite of its very dirty character, the effective density of condensed charge carriers is high compared to the normal state. Zero-field muSR measurements, sensitive to the possible presence of very small magnetic moments, do not show any indications of magnetism that could have been associated with the nearly ferromagnetic Pd atoms.

View original: http://arxiv.org/abs/1307.6386