Abstract
A new model for predicting work functions of binary compounds is proposed which is based on the idea of gas adsorption on metal surfaces. The work function of a compound AB is determined by the higher work function element, B, which is perturbed by "adsorption" of lower work function element, A, as φAB=φB-0.88riA(0.74 φB-0.44 φA-0.64), eV where riA is the ionic radius of the element A in Angstrom. The equation is tested for the work functions of rare earth borides, sulphides, and carbides. Agreement is found to be good. The model is also compared with our previously developed "perturbation" model.