Superconducting Properties of Re 2 Zr 0.5 Hf 0.5 and Re 6 Zr 0.5 Hf 0.5 Alloys

Unconventional superconductivity remains a central research frontier in condensed matter physics. Rhenium‐based compounds have recently attracted interest for their intriguing superconducting properties, including signatures of time‐reversal symmetry breaking (TRSB), making them promising candidates for hosting unconventional states. Here, we synthesize and investigate two Re‐based alloys, centrosymmetric hexagonal Re 2 Zr 0.5 Hf 0.5 and noncentrosymmetric α‐Mn Re 6 Zr 0.5 Hf 0.5 . Comprehensive measurements of electrical resistivity, magnetization, and specific heat confirm bulk type‐II superconductivity with transition temperatures of T c = 6.10(2) K for Re 2 Zr 0.5 Hf 0.5 and 6.27(3) K for Re 6 Zr 0.5 Hf 0.5 . Specific heat and electron–phonon coupling analyses indicate that both compounds are moderately coupled, fully gapped superconductors, providing a valuable platform to explore the interplay between disorder and unconventional pairing.