Polycrystalline Zr5Al4 was synthesized using the arc-melting method. Powder X-ray diffraction confirms the previously reported crystal structure of the Ti5Ga4-type () with lattice parameters: a = 8.4312(6) A°, and c = 5.7752(8) AA°. Electrical resistivity and low-temperature magnetic susceptibility measurements indicate that Zr5Al4 exhibits superconducting behavior below 2 K. The normalized heat capacity jump at Tc = 1.82 K, δC/γTc = 1.50, confirms the bulk superconductivity. The Sommerfeld coefficient γ = 28.5 mJ mol-1K-2 and the Debye temperature ΘD = 320 K were obtained by fitting the low-temperature heat capacity data. The electron-phonon coupling strength λel-ph = 0.49 and estimated upper critical field μ0Hc2(0) = 1.09 T (dirty limit) suggest that Zr5Al4 is a weakly coupled type-II superconductor. First-principles calculations show the presence of a van Hove singularity near the Fermi energy.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)