Growth and structural characterization of Ni/Co superlattices

Ferromagnetic/ferromagnetic Ni/Co superlattices have been grown by molecular-beam epitaxy on Al₂{O}₃$(112{}0) substrates. X-ray diffraction and surface analysis techniques (low-energy electron diffraction and Auger-electron spectroscopy) show that the superlattices grow epitaxially, both Ni and Co in the fcc structure, and with the (111) direction normal to the surface. The superlattices are single crystalline in the growth direction, have an approximately square chemical modulation wavelength, and show four different types of in-plane domains. The lattice parameters measured in the (111) direction are consistent with Co and Ni maintaining their bulk lattice parameters. In the plane of the superlattice, the two materials are lattice matched.