Microscopic Theory of Damon-Eshbach Modes in Ferromagnetic Films
  The surface spin wave branches in ferromagnetic films are studied using a microscopic theory which considers both magnetic dipole-dipole and Heisenberg exchange interactions. The dipole terms are expressed in a Hamiltonian formalism, and the dipole sums are calculated in a rapidly convergent form. The Damon-Eshbach surface modes are analyzed for different directions of the spin-wave propagation and also for different ratios of the strength of the dipole interactions relative to the exchange interactions. Numerical results are presented using parameters for Fe and GdCl$_3$. 
R. V. Leite and R. N. Costa Filho (Departamento de Fisica,   Universidade Federal do Ceara, Brazil.)