A model for alloy formation is used in which the electrochemical or charge-transfer effects are governed by the difference in the electronic chemical potential $\mu$ of the pure metals, provided that the pure metals are previously expanded or compressed in order to have the same electron density ${\rho }_b$ at the boundary of the atomic cells. Then, a comparison of the curves $\mu =\mu \left({\rho }_b\right)$ corresponding to different transition metals reveals that the curves are parallel and that $\Delta \mu$ is almost independent of ${\rho }_b$. This permits us to characterize each metal by one "electronegativity" parameter, and the scale obtained correlates well with the empirical scales of Pauling and Miedema. It also explains why the same set of electronegativity parameters describes liquid and solid alloys in Miedema's empirical theory of heats of formation.

• Received 25 September 1978

DOI:https://doi.org/10.1103/PhysRevB.19.3889