It has been reported that the insulting properties of the barrier layer significantly affect the uniformity and quality of the depositing material . Therefore, handling of the barrier layer during deposition of secondary material in the nanopores of AAO is very essential and important. Until now, three different kinds of electrochemical deposition BAY 63-2521 cell line methods are applied for filling the pores of AAO template: direct current
(DC) electrodeposition , pulse electrodeposition (PED) , and alternating current (AC) electrodeposition . Filling of AAO pores with metallic or magnetic nanowires via direct current (DC) electrodeposition is a tedious Selleckchem R406 process and requires many steps. For instance, first AAO template has to be isolated from Al substrate, and this is achieved by dissolving the Al substrate in a toxic saturated solution of HgCl2. Subsequently, the barrier layer has to be etched away using chemical etching which often leads to the non-uniform widening of pores at the bottom. This process produces AAO template with different
pore diameters at the top and the bottom surface; resulting in non-uniform-diameter nanowires which is undesirable in device fabrication. Finally, a thin metallic contact is sputtered on one side of AAO which act as a cathode during electrodeposition. These steps are time consuming, and additionally, the handling of a fragile AAO template during the whole process is a very difficult task. Furthermore, electrodeposition via direct current in the pores of AAO without modification of barrier layer is generally LY294002 mw unstable
and leads to a non-uniform filling of the AAO nanopores ever due to the cathodic side reaction . PED method is also widely used for the fabrication of metallic or magnetic nanowires in the nanopores of AAO templates. Ni [16, 25] and Co [27, 28] nanowires have been fabricated in the nanopores of AAO applying this method. Although the uniformity and pore-filling efficiency increased many folds compared to DC electrodeposition; however this method also needs modification of the barrier layer [16, 25–28]. In contrast, AC electrodeposition is a very powerful technique and it does not need the detachment of AAO template from the Al-substrate or modification of the barrier layer. Moreover, the Al-substrate is used as cathode during electrodeposition. To the best of the author knowledge, Co-Ni binary alloy nanowire electrodeposition in the AAO template without modification of the barrier layer has not been reported to date. In this study, the fabrication of dense Co-Ni binary alloy nanowires within the nanopores of AAO templates via AC electrodeposition has been reported. Co-Ni binary alloy nanowires with different composition were co-deposited into the nanopores of AAO templates from a single sulfate bath of Co and Ni without modifying the barrier layer at room temperature.