Flux flow and critical currents in an amorphous superconductor Zr₈₅Si₁₅

Studies have been performed on the resistive states in the superconducting mixed state of the amorphous binary alloy Zr₈₅Si₁₅(T_c=2.71K) prepared by the improved liquid quenching technique. Observed critical currents are extremely low so that the flux flow resistivity can be well defined in the whole range of the magnetic field except just below H_c2 where sharp peak effect appears. We obtained the GL parameter κ=130 and GL coherence lengths ξ^{{black star}} (0)=70 A ̊ that can be estimated from H^{{black star}} _c2(0), the extrapolated value using the Kim's law. It is the amorphous state that brings about a high κ and extremely "soft" type II superconductivity.