Diameter-dependent properties of electrodeposited nickel nanowire arrays

The present work investigates the influence of diameter on the different properties of nickel nanowire arrays, electrodeposited into track-etched polycarbonate membrane used as template. Field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the morphology and elemental composition of nanowires having diameter 100, 80 and 50 nm. Synthesized nanowires have same diameter and length as that of pore size and thickness of respective templates. Nickel nanowires are polycrystalline in nature and have face-centred cubic structure as revealed by X-ray diffraction (XRD). The ferromagnetic behaviour of nickel nanowires has been studied by vibrating sample magnetometer (VSM). The coercivity and squareness ratio were determined, and both the parameters increase with decrease in diameter. A broad peak due to surface plasmon resonance (SPR) has also been observed in UV-visible absorption spectra. I-V characteristics curve showed ohmic behaviour in both forward and reverse biasing. Field emission behaviour was studied for nickel nanowire arrays, and the parameters like maximum emission current density, field enhancement factor and turn-on field have been estimated for the fabricated nanowire arrays.