Fabrication of high aspect ratio Co nanowires with controlled magnetization direction using ac and pulse electrodeposition

Abstract

High aspect ratio cobalt nanowire arrayswere fabricated using ac and pulse electrodeposition techniques into the porous alumina templates. ThepHwas adjusted to be about 4. The effects of electrodeposition time in both the ac and pulse techniques were investigated. Using ac electrodeposition technique, increasing the deposition time significantly decreased the coercivity and squareness. The coercivity and squareness of about 600Oe and 0.35 were obtained for high aspect ratio Co nanowires, respectively. In the pulse electrodeposition technique, increasing the off-time between the pulses stabilizes the microstructure thereby suppresses the reduction of the coercivity and squareness. A coercivity of about 1400 Oewas seen for high aspect ratio Co nanowires electrodeposited with 200ms off-time and different pulse numbers.