Exchange coupling in Fe/(Mo_1-xRe_x)_n/Fe (100) and (110) multilayers

Abstract

The exchange coupling in sandwiches of layers of pure bcc Mo and random bcc MO₈₈Re₁₂ embedded in an Fe matrix has been studied by the first-principles Green function technique. We have calculated up to 20 layers of the spacer material for the planes (100) and (110) and obtained oscillation periods. The exchange coupling amplitude and periodicity are analysed with respect to two effects: (i) the interface orientation and (ii) the electronic topological transitions (ETTs), resulting in an essential difference between the Fermi surfaces of Mo₈₈Re¹² and pure Mo.