Enhancement of the upper critical field (H_(C2)) in Nb_2Pd(S_(0.9)Te_(0.1))_5 superconducting fibers

摘要

Here, we report the synthesis and characterization of the Nb_2Pd(S_(0.9)Te_(0.1))_5 superconductor. The resultant polycrystalline sample is consists of solid chunks along with mesh of fibers which are grown in thin long rod shapes having length in several millimeters with cross-sectional area around 5×3 μm~2. The normal state of this superconductor behaves abnormally compared to its parent compound (Nb_2PdS_5) which is shown here. In high temperature regime (T > 125K) it follows the power law which is completely different from its parent analog which shows metallicity (linear behavior) in high temperature range. Below this temperature region a broad peak appears centered around T~* ≈ 62K, the origin of this anomaly is unknown right now, followed by a dip which is centered around T' ≈ 23K which may be some sort of electron localization or some gap like excitation which preceding the superconducting transition having onset at Tc (onset)≈ 6.7K. The upper critical field value H_(c2)(0) = 52.24T enhances in these superconducting fibers. Aslamazov-Larkin (AL) theory shows three significant (3D, 1D and short-wave (SW)) fluctuation regimes in these superconducting fibers.