The electronic structure of LaCo₂B₂

College of Physics and Information Engineering, Henan Normal University - Xinxiang, Henan 453007, PRC

^a wgt0771@sina.com.cn

Received: 6 May 2011
Accepted: 24 May 2011

Abstract

The electronic structure of the recently discovered LaCo₂B₂ was studied from first-principles calculations. Our results indicate that the hybridization between Co-3d and B-2p is much stronger than that between Fe-3d and As-4p in LaOFeAs and BaFe₂As₂, which removes the magnetic ordering of Co ions. Therefore, the ground state of LaCo₂B₂ is nonmagnetic. At the Fermi level, the density of state of La-5d is very high and here are four bands cutting across the Fermi level, which are mostly derived from d_z²−3r² and d_yz/zx orbitals. Such results are different with both LaOFeAs and BaFe₂As₂. The substitution of La by Y atoms would not change the ground state, while substitution of La with Sc atoms might induce a magnetic moment on the Co atom. Comparing with LuNi₂B₂C₂, we classify LaCo₂B₂ as a BCS superconductor.