Anisotropic Superconducting Properties of FeSe_0.5Te_0.5 Single Crystals

Abstract Anisotropic electrical transport and magnetic properties of FeSe0.5Te0.5 single crystals, which are grown by the self-flux method, have been investigated. The in-plane resistivity shows a metallic-like temperature-dependence, while the out-of-plane resistivity shows a broad lump with maximum at around 64 K. The magnetization loops for H//c-axis and H//ab-plane are also different, for example, there is a typical second peak for H//c-axis. The in-plane critical current density is larger than the out-of-plane one. The coherence length and penetration depth are estimated by the Ginzburg-Landau theory. The anisotropic parameter γ depends on the applied magnetic field and the temperature. The coupling of superconducting FeSe(Te)-layers and the flux pinning mechanism relevant to anisotropy are also discussed.