Anisotropic magnetization of epitaxial Ni nanogroove-arrays prepared by reduction of self-organized oxides

► Ni (1 1 1) epitaxial nanopatterns were formed on sapphire by self-organizing process. ► The nanopattern comprises thousands of straight, parallel and periodic nanogrooves. ► The process includes growth of NiO (1 1 1) by LaserMBE and annealing in air and H2. ► The pattern retained its surface topography and epitaxy after the H2 reduction. ► We report in-plane anisotropic magnetization behavior attributed to the morphology.