Nonmetallic Low-Temperature Normal State of K0.70Fe1.46Se1.85Te0.15
Abstract
The normal-state in-plane resistivity below the zero-field superconducting transition temperature Tc and the upper critical field Hc2 were measured by suppressing superconductivity in pulsed magnetic fields for K0.70Fe1.46Se1.85Te0.15. The normal-state resistivity ab is found to increase logarithmically with decrasing temperature as TTc→ 0. Similar to granular metals, our results suggest that a superconductor - insulator transition below zero-field Tc may be induced in high magnetic fields. This is related to the intrinsic real-space phase-separated states common to all inhomogeneous superconductors.
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