Oscillation in the Interlayer Coupling of Fe Films Across Cr Films Measured by Means of Light Scattering from Spin Waves and M(H)-Curves

Abstract

AbstractBy means of light scattering from spin waves and magnetooptical Kerr measurements we investigated the exchange interaction of two Fe films across a Cr film as a function of the Cr thickness dCr.Using good quality epitaxial samples with a special wedge geometry of the interspacer we observed up to four full periods of the long range oscillations of the exchange, including its ferromagnetic parts. At room temperatures the damping of the oscillations does not follow the d-2Crpendence predicted by zero-temperature RKKY-type theory.After a special e-beam treatment of the samples a short-range oscillation with a period around a lattice constant of Cr are discovered. The value of coupling in the maximum in this case shows considerable temperature dependence.The analysis of domain patterns and M(H) curves reveals the existence of a noncollinear interaction, which causes a configuration where the magnetizations of two Fe films are perpendicular to each other.