Band structure of a new (16–18 K) superconductor LiFeAs compared to Li0.5FeAs and LiCoAs

The band structure of a new (16–18 K) superconductor LiFeAs, as a possible first representative of the third (the so-called 111) group of phases, which, along with the groups of four-component 1111 oxyarsenides LnOFeAs and three-component 122 arsenides AFe₂As₂, belong to the family of new high-temperature (26–56 K) FeAs superconductors, has been studied using the ab initio full-potential augmented-plane-wave method and the generalized-gradient approximation. The structure, energy bands, densities of state, Fermi surface, low-temperature electron specific heat γ, and molar Pauli magnetic susceptibility for LiFeAs are discussed and compared to similar data for the systems simulating the hole (Li_0.5FeAs) and electron (LiCoAs) doping of LiFeAs.