Upper critical field of quasi one-dimensional superconductor (DMET-TSeF)2AuI2 under oriented magnetic fields ☆

Abstract The superconductivity of quasi one-dimensional salt (DMET-TSeF) 2 AuI 2 was studied in the oriented magnetic fields through the resistive measurement. The upper critical fields H c2 in the magnetic fields parallel to the highest and intermediate conductive a - and c -axes tend to exceed the Pauli paramagnetic limit. However, it is difficult to determine these values because the behaviour below 0.3 K is obscured by an electronic phase transition. The coherence lengths are evaluated from the slopes of H c2 ( T ) curves near T c as ξ a (0)≈100 nm, ξ b (0)≈2 nm, ξ c (0)≈30 nm.