Electrodeposition of epitaxial nickel films on GaAs

The structural and magnetic properties of Ni films grown by electrodeposition from simple sulfate solutions directly onto the (0 0 1) and (0 1 1) surfaces of n-GaAs have been studied. In-plane X-ray diffraction has been used to show that Ni grows on (0 0 1) GaAs with two different preferred epitaxial relationships: (1) perpendicular to plane (0 0 1)_Ni(0 0 1)_GaAs and preferred orientation in-plane 1 0 0]_Ni1 1 0]_GaAs and (2) perpendicular to plane (0 1 1)_Ni(0 0 1)_GaAs and preferred orientation in-plane 1 1 1]_Ni1 1 0]_GaAs. Nickel films grown on (0 1 1) n-GaAs show only a single preferred growth relationship: perpendicular to plane (1 1 1)_Ni(0 1 1)_GaAs and in-plane 1 1 0]_Ni1 1 0]_GaAs. The magnetic properties were strongly dependent on the substrate orientation. The films grown on GaAs (0 0 1) showed a small but definite four-fold magnetic anisotropy in plane with the highest remanence being found along the GaAs 1 0 0] direction. In contrast, the Ni films grown on the (0 1 1) GaAs showed a pronounced uniaxial anisotropy with an anisotropy field of approximately 500 Oe.