AN ABINITIO STUDY OF THE MAGNETIC-ANISOTROPY OF FEN/CU(AG)M MULTILAYERS

The magnetocrystalline anisotropy energies of Fe(n)/Cu(Ag)m multilayers (n(m) = 1 (5), 3 (3), 5 (3)) have been calculated with the relativistic spin-polarised band theory. For all multilayers considered (except Fe5/Ag3), the easy axis of magnetisation is predicted to be perpendicular to the Fe monolayer plane. This perpendicular magnetic anisotropy is found to originate in the large anisotropy of the interface electronic structure which overcomes the in-plane anisotropy due to the magnetic dipolar interaction. The results also suggest that for ultrathin ferromagnetic Fe films in noble metal substrates, the perpendicular magnetic anisotropy switches to the in-plane one when the number of Fe monolayers is greater than five.