We describe three previously unreported superconductors, BaPb3, Ba0.89Sr0.11Pb3, and Ba0.5Sr0.5Pb3. These three materials, together with SrPb3, form a distinctive isoelectronic family of intermetallic superconductors based on the stacking of Pb planes, with crystal structures that display a hexagonal to cubic perovskite-like progression, as rarely seen in metals. The superconducting transition temperatures (Tc) are similar for all -2.2K for BaPb3, 2.7K for Ba0.89Sr0.11-Pb3, and 2.6K for Ba0.5Sr0.5Pb3, and the previously reported Tc of SrPb3, ∼2K, is confirmed. The materials are moderate coupling superconductors, and calculations show that the electronic densities of states at the Fermi energy are primarily contributed by Pb. The observations suggest that the Pb-stacking variation has only a minor effect on the superconductivity.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)