In-plane momentum conservation in Fe/Cr/Au/Fe(001) layered structures

We study the effect of an Au layer at one of the Cr/Fe interfaces in epitax ial Fe/Cr/Au/Fe(001) sandwich structures on the magnetic interlayer couplin g behavior by magneto-optical Kerr effect measurements and on the growth by scanning tunneling microscopy. The main effect of the Au layer is the supp ression of the long-period oscillations of the magnetic interlayer coupling , while the short-period oscillations become dominant although their amplit ude is stronger attenuated than proportional to D-2?, where D is the total thickness of the nonferromagnetic spacer layers. These findings are explain ed with the shapes of the Fermi surfaces of the spacer materials (Au and Cr ) and in-plane momentum conservation at the Cr/Au interface of the electron s that mediate the coupling. This interpretation implicates that the N-cent ered ellipse of the Cr Fermi surface is the origin of the long-period oscil lations across Cr spacers. [S0163-1829(99)51030-8].