Abstract
with a -type (so-called “122”) structure composed of alternately stacked La and CoB layers exhibits metallic electrical conductivity and Pauli paramagnetic behavior down to 2 K. Bulk superconductivity with a of emerges upon substituting with dopant elements, i.e., isovalent substitution to form , or aliovalent substitution to form . According to the density functional theory calculations, highly covalent bonding between Co dominating the Fermi level and levels deeper than the Fermi level removes magnetic ordering from Co electrons even in the undoped samples. This is a first Co-based superconductor among the 122-type family.
- Received 6 February 2011
DOI:https://doi.org/10.1103/PhysRevLett.106.237001
© 2011 American Physical Society