Electronic rule for formation of glassy alloys

The glass transition temperature T-g of 100 kinds of glassy alloys can be expressed as a function of their valence electron concentration (VEC): T-g=131VEC+57 for metal/metal bonding type and T-g=-236VEC+2375 for metal/metalloid bonding one. The electron valences of the constituent elements of the glassy alloys are somewhat larger than those predicted by crystalline metallic valence bond theory, suggesting a valence electron contribution associated with spd or spf hybridization for glass formation. Ab initio molecular orbital calculations of the optimized structures for Mg monoanion clusters warranted application of the valence electron rule. (c) 2007 American Institute of Physics.