Electrochemical Deposition of Nanowires in Porous Alumina

Abstract

Electrochemical deposition is a very efficient method for producing many types of modern materials. The method is not expensive and does not have a limit for sample size. In our work the preparation of Ni, Co and Fe nanowires is presented. The obtained nanowires had different diameter and length which were tunable by template porous material and time of deposition, respectively. The quality of the prepared wires was dependent also on deposition mode. The smallest wires of the diameter around 40 nm were prepared in porous anodic alumina oxide obtained from oxalic acid. The largest ones, around 120 nm, were produced in phosphoric acid. The length could be as large as the thickness of the oxide and reached up to about 1 µm. The morphology of wires was studied by atomic force microscopy and scanning electron microscopy. The magnetic characterization was done with usage of magnetic force microscopy and the Mössbauer spectroscopy. The wires show magnetization along their growth direction.

Ultra-long Fe nanowires by pulsed electrodeposition with full filling of alumina templates

“…On the other hand, ac methods only require the reduction of the barrier layer thickness (δb) to perform deposition, given the alternate polarization pulse that allows discharging the alumina capacitance. The most common approach to reduce δb is to perform a pore widening process in a bath containing phosphoric acid (H3PO4) at 30 °C [1,3,[17][18][19]. For the particular case of the electrodeposition of Fe NWs, both methods have been reported.…”

Magnetic nanowires (Fe, Fe-Co, Fe-Ni) – magnetic moment reorientation in respect of wires composition

“…Templates for wires deposition were obtained by anodization of aluminum in acidic solution under current conditions appropriate for the growth of the required pores diameter [11]. The details of the preparation of the matrices were described elsewhere [12,13].…”

Stability of core–shell nanowires in selected model solutions

“…To obtain Fe nanowires, porous aluminum oxide (AAO) matrixes were used, prepared as described in previous papers [14][15][16][17]. Fe nanowires were fabricated by the 3-step anodization method in 10% phosphoric acid, which gives pores of a diameter smaller than 200 nm.…”