Electrodeposition of Ni/Co and Ni Magnetic Nanowires Using Allumina Template

Abstract

Nickel and nickel-cobalt alloy nanowires were fabricated through template-assisted electrochemical deposition method and sandwiched between two caps of electrodeposited pure gold. Free standing porous alumina templates were prepared and used for the synthesis of the ordered nanowires. The morphology and composition of as-deposited nanowires were determined by scanning electron microscope. Nanowires were characterized by a diameter of 70 nm, as the alumina template pores diameter, and by a length in the range of 2-3 μm. Backscattered electron signal showed the presence of Au and Ni or Ni-Co sandwich, highlighting a well defined and void free interface between the gold caps and the Ni or Ni-Co layer. Particular optimization has been considered for the subsequent magnetoresistance characterization of nanowires. Angular dependence of magnetoresistance has been measured as a function of temperature from in-plane to perpendicular magnetic field configuration. Anisotropic magnetoresistive measurements suggested a magnetization process by magnetization rotation from nanowire axis towards in-plane orientation.