Penetration of electromagnetic fields through multilayered and cluster-layered Fe/Cr nanostructures

Abstract

The transmission of millimeter-wavelength electromagnetic waves through Fe/Cr superlattices has been investigated. Measurements were conducted at frequencies from 26 to 38 GHz in dc magnetic fields of up to 14 kOe. It has been shown that changes in the modulus of the coefficient of transmission through the superlattice are caused by two physical mechanisms: changes in the surface impedance due to the Joule losses and the precession of the magnetic moment under the conditions of ferromagnetic resonance (FMR). The giant magnetoresistive effect and changes in the microwave transmission coefficient have been compared. The FMR spectra of the acoustic branch that were calculated within the model of biquadratic exchange using the magnetization curves proved to be close to the experimental spectra. The exchange constants were estimated. The Gilbert damping parameter upon microwave transmission was estimated from the FMR-line width. Copyright © 2005 by Pleiades Publishing, Inc.