A Heisenberg model of a two-component magnetic superlattice

Abstract

We study an (m, n) superlattice consisting of two alternating magnetic materials (components) of m and n atomic layers, respectively. The superlattice is modelled by a simple cubic lattice of spins coupled via nearest-neighbour exchange (Heisenberg model). Using recurrence relations, the dispersion equations of surface and bulk spin waves are derived for both finite and semi-infinite systems. The numerical results of the (1, 1), (3, 1) and (3, 2) cases are shown graphically. For a range of the surface exchange Js, the maximum number of surface modes, equal to m+n, is obtained.