AMORPHOUS MAGNETISM IN IRON-BORON SYSTEMS - 1ST-PRINCIPLES REAL-SPACETIGHT-BINDING LMTO STUDY

We have performed ab initio spin-polarized self-consistent calculation s of the electronic structure and magnetic moments in the series of th e Fe100-xBx glasses (0 < x < 60) with the real-space tight-binding LMT O method. Realistic atomic models consisting of 500 to 864 atoms in a cubic box with periodic boundary conditions were constructed with the use of the Monte Carlo method. The systems studied show itinerant magn etism with the net magnetic moment on iron sites, muBAR, saturating at the maximum value in a region of a (hypothetical) amorphous iron. The iron magnetic moment decreases upon dilution with boron atoms with no maximum on the compositional dependence of muBAR. The calculated dist ribution of the iron moments is narrow with the width decreasing towar ds the boron-rich end of the series. The magnetovolume effect is shown to be noticeable in iron-rich glasses, declining with increasing boro n content. No evidence of a tendency to form the spin-glass state has been found in iron-rich borides.