Chemical ordering of epitaxial FePd deposited on ZnSe and the surfactant effect of segregated Se

Abstract

We describe the experimental conditions under which a thin film (500 Å thick) of the ferromagnetic alloy FePd can be grown epitaxially onto a thin (100 nm thick) ZnSe(001) layer on a GaAs(001) substrate. A two-dimensional growth could be achieved by using a Pt seeding layer inserted between FePd and ZnSe. During the growth of the metallic layers, the segregation of Se atoms at the surface involves a dramatic effect on the formation of the uniaxial L10 FePd ordered phase. As a result, no perpendicular magnetic anisotropy was observed. The removal of the Se atoms from the Pt surface by a gentle ion bombardment, enables the growth of a FePd layer exhibiting a large anisotropy constant of about 1.2×107 erg/cm3 along the growth direction with a marked perpendicular magnetic domain configuration.