Growth of nanosized MnAs/Si(111) magnetoelectronic heterostructures and their magnetooptical study

Thin (6-12 nm) epitaxial MnAs films were MBE-grown on Si(111) substrates un der different technological conditions. The films feature essentially diffe rent surface morphology. This manifests itself in the formation, on the sil icon surface, of hexagonal-shaped crystallites, whose dimensions vary depen ding on the growth conditions. The volume and surface magnetic properties o f the films were studied using the magnetooptical Kerr effect and optical s econd harmonic generation. The Kerr effect was found to scale linearly with the effective thickness of the magnetic layer. The thickness of the magnet ically disordered transition layer formed near the interface with the subst rate was estimated. The surface and volume hysteresis properties of the fil ms were found to be different. A contribution to the second-harmonic intens ity was observed which is an odd function of magnetization. This effect ori ginates from the interference of the magnetic and nonmagnetic contributions to the nonlinear polarization. (C) 2001 MAIK "Nauka/Interperiodica".