Ferromagnetic Resonance in Superlattices Fe/Cr on MgO

Abstract
Measurements of ferromagnetic resonance (FMR), magnetization and magnetoresistance (Δρ/ρ) have been made for Fe(30 Å)/Cr(x) superlattices epitaxially deposited on MgO(001) substrates, to study the antiferromagnetic (AF) coupling between the adjacent Fe layers. For x=6-12 Å films, a large Δρ/ρ (>5%), high saturation field (H s) and two FMR peaks were observed. A model of strongly coupled AF magnetization explains the high H s; however, it cannot explain the observed low field values of the secondary FMR peak.