Electronic and magnetic properties of Fe-Cu superlattices

G.FABRICIUS; ANA MARÍA LLOIS; M.WEISSMANN

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 1994 vol. 6 p. 5017 - 5024

0953-8984

The electronic and magnetic properties of FeICu superlatices grown in the (1 I I ) direction, for which Fe Ukes Ihe RC structure, are studied with a parametrized tight-binding Hamiltonian. The splitting between majority and minority d bands is rehted to an effectiveexchange parameter 3 that we adjust to obtain within our model the bulk magnetization for BCC Fe. As the magnetization of bulk m Fe is very sensitive to this parameter we study the magnetic properties as a function of it. We find that the 2Fe12Cu superlattice is possiblyferromagnetic and that 3Fei3Cu has more than one stable state (paramagnetic, ferromagnetic or ferrimagnetic) with quite similar energies. As recent experimental results detect a small magnetic moment for h i s last superlattice, comparison with the calculations suggest that they are ferrimagnetic. Comparison wilh calculations for ZFe and 3Fe m(I 11) freestanding slabs show that lhe ZFeOCu and 3Fe43Cu superlattices behave as low-dimensional systems. the effeclof Cu king to slightly reduce the magnetic moment per atom of Fe with respect to a free-standing slabs.