Fabrication of Nanowire Arrays Using Diblock Copolymer

Abstract

Electrodeposited Co nanowires were grown on self assembled diblock copolymer nanoporous templates. While keeping the template pore size and electrolyte pH value constant at 13.7 nm and 3.82, respectively, the DC current density (5 mA/cm2 and 50 mA/cm2) and time of deposition (50s, 100s, 150s and 200s) were varied as an attempt to obtain nanowires of varied aspect ratios and morphologies. It was observed that height of the nanowire linearly enhances with the time of the electrodeposition. SEM images of the samples indicate that the template pores were completely filled during deposition when the current density was set 50 mA/cm2. Excess times of deposition produced a thin layer of the deposited material on top of the porous template. Magnetic hysteresis properties of the generated nanowires were examined by vibration sample magnetometry. The loops displayed are highly square with coercivities of few tens of oersteds. The magnetization of the Co nanowires enhances as the height of the wires increases. The results were analyzed to understand the influence of current density on the growth of nanowires.