MAGNETIC-PROPERTIES OF SEMI-INFINITE SYSTEMS OF CR(FE) ON A FE(CR) (001) SURFACE

We have investigated the magnetic properties of semi-infinite systems of n (n = 1-5) overlayers of Cr(Fe) on the Fe(Cr) (001) surface by means of self-consistent tight-binding calculations in the framework of the Hubbard Hamiltonian within the unrestricted Hartree-Fock approximation including s, p and d electrons. Particularly, we have obtained a decrease of the magnetic moment of Cr at the interface of Cr(n)Fe(001) and Fe(n)Cr(001), when the number of layers n increases. The same effect, although less pronounced, appears for iron at the interface of Fe(n)Cr(001), whereas the contrary happens at the interface of Cr(n)Fe(001). The general results can be understood in terms of the competition between a surface effect and the antiparallel alignment of spins of Fe and Cr atoms.