Anisotropic magnetoresistance of ni nanorod arrays in porous SiO2/Si templates manufactured by swift heavy ion-induced modification

Abstract

In this work anisotropic magnetoresistance in nanogranular Ni films and Ni nanorods on Si(100) wafer sub-strates was studied in wide ranges of temperature and magnetic field. To produce Ni films and nanorods we used electrochemical deposition of Ni clusters either directly on the Si substrate or into pores in SiO2 layer on the Si substrate. To produce mesopores in SiO2 layer, SiO2/Si template was irradiated by a scanned beam of swift heavy 350 MeV 197Au26+ ions with a fiuence of 5 108 cm2 and then chemically etched in diluted hydrofiuoric acid. Pores, randomly distributed in the template have diameters of 100-250 nm and heights about 400-500 nm. Com-parison of temperature dependences of resistance and magnetoresistance in Ni films and n-Si/SiO2/Ni structures with Ni nanorods showed that they are strongly dependent on orientation of magnetic field and current vectors relative to each other and the plane of Si substrate. Moreover, magnetoresistance values in n-Si/SiO2/Ni nano-structures can be controlled not only by electric field applied along Si substrate but also by additionally applied transversal bias voltage.