  Chemisorption on ferromagnetic and non-magnetic surfaces is discussed within
the Newns-Anderson-Grimley model along with the Stoner model of ferromagnetism.
In the case of ferromagnetic surfaces, the adsorption energy is formulated in
terms of the change in surface magnetic moments. Using such a formulation, we
address the issue of how an adsorbate's binding strength depends on the
magnetic moments of the surface and how the adsorption process reduces/enhances
the magnetic moments of the surface. Our results indicates a possible
adsorption energy scaling relationship in terms surface magnetic moments. In
the case of non-magnetic surfaces, we formulate a modified stoner criterion and
discuss the condition for the appearance of magnetism due to chemisorption on
an otherwise non-magnetic surface.
