Interlayer Exchange Coupling: The Effect of Substitutional Disorder

Abstract
The effect of substitutional disorder on the interlayer exchange coupling is studied, with focus on the role of the “vertex corrections.” It is proved, on general grounds, that, to first order, the latter do not contribute to the exchange coupling, due to exact cancellation. The applicability of this result for realistic systems is supported by first-principle calculations within the coherent potential approximation, for various disordered systems.