Light scattering from surface and bulk thermal magnons in iron and nickel

Abstract

We report on light scattering measurements on thin polycrystalline samples of iron and nickel. Both the surface and bulk magnons are observed. The measured magnon energies as a function of magnetic field, and of wavevector magnitude and direction, are in good agreement with the calculated values. The predicted exchange induced decay of the surface magnon is observed. In nickel the observed frequencies and linewidths are strongly strain dependent. Oxide layers have an almost negligible effect on the spin wave frequencies in both iron and nickel.