Publications Repository - Gdańsk University of Technology

Superconductivity is observed with critical temperature Tc = 2.0 K in self-flux-grown single crystals of CaBi2. This material adopts the ZrSi2 structure type with lattice parameters a = 4.696(1) Å, b = 17.081(2) Å and c = 4.611(1) Å. The crystals of CaBi2 were studied by means of magnetic susceptibility, specific heat and electrical resistivity measurements. The heat capacity jump at Tc is DC/gTc = 1.41, confirming bulk superconductivity; the Sommerfeld coefficient g = 4.1 mJ mol1 K2 and the Debye temperature YD = 157 K. The electron–phonon coupling strength is lel–ph = 0.59, and the thermodynamic critical field Hc is low, between 111 and 124 Oe CaBi2 is a moderate coupling type-I superconductor. 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.

Authors

• dr inż. Michał Jerzy Winiarski link open in new tab ,
• B. Wiendlocha,
• Sylwia Gołąb,
• S. K. Kushwaha,
• Piotr Wiśniewski,
• Dariusz Kaczorowski,
• Joe D. Thompson,
• Robert J. Cava,
• prof. dr hab. inż. Tomasz Klimczuk link open in new tab