Theory of Oscillatory Exchange Coupling in Fe/(V,Cr) and Fe/(Cr,Mn)

Using a first-principles method, we determined the composition and orientation dependence of oscillatory exchange coupling in bcc $\mathrm{Fe}/{\mathrm{V}}_x{\mathrm{Cr}}_{1-x}$ and $\mathrm{Fe}/{\mathrm{Cr}}_{1-y}{\mathrm{Mn}}_y$ magnetic multilayer alloys for $0<x<\mathrm{}1\mathrm{}$ and $0<y<\mathrm{}0.3\mathrm{}$. For the [001] and [110] orientations, the coupling was oscillatory and well described by the superposition of two well-separated RKKY-like components. The composition dependence of the coupling amplitudes and periods shows a rich variety of features. These are discussed and compared with experiment and the predictions of simplified models.