Phase Diagram and Superconductivity: New Insight into the Fundamentals of InSn Bimetallic Alloys

We report the crystal structure and superconducting phase diagram for In_pSn_1–p (0.01 ≤ p ≤ 0.99) bimetallic alloys. A weak electron–phonon coupling was observed in intergranular linked InSn superconductors over an infinite range mediated by high-energy phonons. An enhanced T_C(0) ∼ 6.2 K and critical field H_C(0) ∼ 2.7 kOe were determined from intermediate (γ-Sn + β-InSn) composite alloys attributed to internal strain possibly originating from thermal expansion effect of constituent phases.