Calculated magnetic moments and electronic structure of the compounds Rn+1Co3n+5B2n, R = Gd, Tb, n = 0, 1, 2, 3 and ∞

The compounds of the Rn+1Co3n+5B2n family crystallize in a hexagonal structure having the P6/mmm space group. The ab initio spin-polarized band structure calculations have been performed based on the tight-binding linear muffin-tin orbitals method (TB LMTO) for the following five representatives of the family: RCo5, RCo4B, R3Co11B4, R2Co7B3 and RCo3B2, where R=Gd or Tb. The cobalt atoms occupying distinct sites have different types and numbers of neighbouring atoms and as a consequence the magnetic moments are different. The calculated values are compared with the bulk measurements.