Orientational dependence of the oscillatory exchange interaction in Co/Cu/Co

A strong oscillatory exchange coupling has been discovered in epitaxial (111) and (110) Co/Cu/Co sandwiches with wedge-shaped Cu layers, deposited by molecular-beam epitaxy (MBE) on single-crystal substrates. This finding proves the intrinsic nature of the strong antiferromagnetic coupling in (111)-textured sputtered Co/Cu multilayers. Combined with recent results on (100) Co/Cu/Co MBE-grown samples, it becomes evident that the nature of the oscillations in Co/Cu/Co depends markedly on growth direction, agreeing with predictions invoking the topology of the Fermi surface of the interlayer Cu.