Possibility of various magnetic configurations in the Cr (Fe) monolayer deposited on vicinal surfaces of Fe (Cr).

Abstract

The local magnetic moments and magnetic order are calculated for a Fe (Cr) monolayer adsorbed on semi-infinite Cr (Fe) substrates with high-index surfaces. These stepped interfaces are present in the wedge-shaped configurations recently analyzed by different experimental groups in order to investigate the interlayer magnetic coupling in Fe/Cr/Fe systems. The spin-polarized electronic distribution is obtained by solving self-consistently a d-band model Hamiltonian in the mean-field approximation within the framework of the tight-binding real-space method. Several magnetic configurations have been found for all the systems investigated. In the most stable configuration of the Cr monolayer on Fe vicinal surfaces, the local moments of most of the Cr atoms are antiferromagnetically coupled with the Fe moments, an exception being the Cr atoms at the edge of the step. Cr atoms at nearest-neighbor positions (located at the kink and edge of the steps) are always antiferromagnetically coupled. For the Fe monolayer on Cr vicinal surfaces, the average magnetization at the surface results is zero for the two most stable solutions. However, other metastable solutions with net average magnetization on the Fe overlayer are found. The Fe atoms at the edge and kink of the steps (first neighbors) are, in all cases, ferromagnetically coupled. These results are in qualitative agreement with recent experimental observations.