Oscillating Interlayer Coupling of (111) Co/Cu 1− x Ni x Sputtered Multilayers

The periodicity of the interlayer exchange coupling vs . the non-magnetic spacer layer thickness of Co/Cu 1− x Ni x (111)-oriented sputtered multilayers is found to increase with x from 12.2 up to 15.8 Å in the range 0 < x < 0.19. This effect is accompanied with a decrease of the AF coupling intensity. We discuss our results in terms of a modification of the Fermi surface of copper due to Ni alloying, in good agreement with theoretical predictions.