Real-space TB-LMTO spin-polarized self-consistent calculations of the electronic structure of the amorphous alloys Ni-B, Fe-B and Zr-Be

Abstract

The first-principles tight-binding (TB)-LMTO method is used for self-consistent calculations of the electronic structure of the amorphous Fe80B20, Ni100-xBx and ZrxBe100-x alloys in combination with the recursion method. Realistic structure models were constructed with the use of the Monte Carlo method. The electron density has been calculated self-consistently for the given amorphous structures. The authors describe their results for the electronic structure of amorphous Fe80B20, which is a typical transition-metal-metalloid glass. In the paramagnetic phase it has a generic double-peak structure close to the Fermi level formed by non-bonding Fe d orbitals, with a bonding B p-Fe d hybrid at lower energies, in agreement with previous calculations. The authors present the spin-polarized LSDA calculations, which show that the d band splits, resulting in a strong itinerant magnetism in Fe80B20 with a net moment on Fe atoms of mu =2.14 mu B, in good agreement with experiment and estimated values from generalized Stoner criteria. By making use of low-temperature heat capacity and magnetic susceptibility data for Ni-B and Zr-Be glasses the authors show good agreement with the calculated DOS at the Fermi level, N(0), if electron-phonon and exchange enhancements are taken into account.