Theory of Indirect Exchange Interaction between Adatoms on the Solid Surface : H/W System

Abstract

Theory of indirect (or super) exchange interaction between a pair of adatoms on the solid surface has been described. It is analogous to the super exchange interaction in Perovskite antiferromagnets. The effective exchange integral J_± has been derived from first principles. The results of numerical calculation of J_± for H/W system show that (1) J_± is negative and amounts to a considerable magnitude, (2) it is of long range (damps slowly and oscillates strongly as a function of the adatom-adatom distance), and (3) Fermi energy and adsorption form (or site) also affect it strongly. Finally antiferromagnetic spin ordering of the adsorbed layer on the surface has been briefly discussed.