Application of the Miedema model to formation enthalpies and crystallisation temperatures of amorphous alloys

Abstract

The function f_B^A-which defines the degree by which an A atom is surrounded by neighbours of B atoms in Miedema's semi-empirical model and is used for the calculation of the formation enthalpy of crystalline alloys-is modified for amorphous alloys. For the five alloy systems considered, the f_B^A function turns out to be well described by f_B^A=c_B^s(1+5(c_A^sc_B^s)²). This f_B^A also reflects the existence of chemical short-range order. In addition, Buschow's prediction for the crystallisation temperature of amorphous alloys is modified using this f_B^A, resulting in the relation T_x=5 Delta H_h^s+275, where Delta H_h^s represents the formation enthalpy of a hole of the same size as the smaller atom.