and 124 Oe. Results of electronic structure calculations are reported and charge densities, electronic bands, densities of states and Fermi surfaces are discussed, focusing on the effects of spin-orbit coupling and electronic property anisotropy. We find a mixed quasi-2D + 3D character in the electronic structure, which reflects the layered crystal structure of the material. Keywords: Type-I superconductivity, 2 I IntroductionMuch effort has recently been devoted to Bi-based candidates for topological insulators [1,2,3]. The presence of the heavy element bismuth provides the strong spin-orbit coupling that is essential for formation of the topologically-nontrivial band structure of these materials. To the best of our knowledge, no report on the physical properties of CaBi 2 has been previously published. CaBi 2 crystallizes in an orthorhombic lattice in non-symmorphic space group Cmcm (no. 63) [19], and is isostructural with ZrSi 2 [21,22]. In order to study the electronic properties of CaBi 2 , we employed a self-flux-based single crystal growth method [32], and the physical properties of the resulting crystals were analyzed. The electronic structure of the system was next calculated, using density functional theory methods. Electronic bands, densities of states, Fermi surfaces and charge densities are described here in addition to the electronic properties of the material; the analysis focuses on spin-orbit coupling effects and the anisotropy of the electronic states. II Materials and MethodsTo grow the CaBi 2 crystals, calcium granules (Alfa Aesar, 99.5%) and bismuth pieces (Alfa Aesar, 99.99%) in a 3:17 molar ratio (15 at% of Ca) were put in a carbon-coated quartz tube inside an Ar-filled glovebox. A plug of quartz wool was then inserted, and the tube was subsequently evacuated and sealed without exposing the Ca metal to air. The ampule was heated to 550ºC, kept at that temperature for 8 hours, and then slowly cooled (3ºC per hour) to 310ºC at which temperature the excess Bi was spun off with the aid of a centrifuge (3000 rpm, Heat capacity and electrical resistivity measurements were performed using a 3 He-refrigerator equipped Quantum Design PPMS system. Electrical contacts were glued to the sample surface using silver paste. A standard relaxation method was used for the heat capacity measurements.Magnetic susceptibility measurements were carried out in a Quantum Design MPMS-XL SQUID magnetometer equipped with an iQuantum 3 He refrigerator.Electronic band structure calculations were performed using the plane-wave pseudopotential III ResultsThe EDS results yielded the Ca:Bi ratio of 1:2, confirming the stoichiometry of the grown crystals. Additionally, some elemental Bi spots on the surface were found. They may originate either from remaining flux material that was not removed during the centrifugation process, or arise from CaBi 2 decomposition in contact with air and moisture. The room temperature PXRD pattern of crushed crystals is presented in Fig. 2 (the increased background in the low 2θ range is due...

We present the crystallographic analysis, superconducting and spectroscopic characterization, and theoretical modeling of CeIr3. Lattice parameters a = 5.2945(1) Å and c = 26.219(1) Å are found for the R-3m symmetry crystal structure, which are close to the literature values. CeIr3 is a moderate type-II superconductor (κGL = 17, λe–p = 0.65) below 2.5 K. Ce ions exhibit a strongly intermediate valence character as evidenced by x-ray photoelectron spectroscopy. The normal state magnetic susceptibility is weakly temperature dependent and follows the inter-configuration fluctuation model with a singlet Ce−4 f 0 ground state. Theoretical calculations support a non-magnetic ground state of the system and reveal that Ir−5d states are dominant at the Fermi level.

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We describe three previously unreported superconductors, BaPb 3 , Ba 0.89 Sr 0.11 Pb 3 and Ba 0.5 Sr 0.5 Pb 3 . These three materials, together with SrPb 3 , 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 (T c ) are similar for all -2.2 K for BaPb 3 , 2.7 K for Ba 0.89 Sr 0.11 Pb 3 and 2.6 K for Ba 0.5 Sr 0.5 Pb 3 , and the previously reported T c of SrPb 3 , ~ 2 K, 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.