Amplitude of ferromagnetic spin-wave resonance in thin films

Abstract

The effect of conductivity on the spin-wave spectrum of thin Permalloy ferromagnetic films has been investigated. If conductivity effects are included and a simple surface anisotropy is assumed, it is known that the calculated mode locations and amplitudes for Permalloy films are in excellent agreement with some experimental data in the range 800–2700 Å in thickness. If conductivity effects are omitted, a much simpler calculation is possible, but the error in mode location and amplitude has been unknown. For both perpendicular and parallel resonance geometries, detailed calculations reported here have shown that mode locations are not significantly affected over the above thickness range, and that the main mode amplitude is in error by only 20% at 800 Å thickness. However, for 2000 Å thickness, the main mode amplitude is in error by a factor of 2.5.