Abstract:
Arrays of nanowires (NWs) with a diameter of 100 nm from Ni and Co have been obtained by matrix synthesis. Nickel samples were obtained at different temperatures of the electrolyte solution, and cobalt samples were obtained at different pH values. The magnetic properties were investigated by vibrational magnetometry. A multiple increase in saturation magnetization and coercive force was found for Ni-NWs with an increase in the electrodeposition temperature from 20 to 60$^\circ$C. A change in the pH of the cobalt electrolyte from 3 to 5 leads to a change in the NW structure, respectively, from cubic to hexagonal, with a noticeable change in magnetic parameters. The NW arrays were irradiated with argon ions with an energy of 15 keV with fluences from 8.6 $\cdot$ 10$^{11}$ to 6.3 $\times$ 10$^{15}$ cm$^{-2}$. When Co-NWs (with a hexagonal lattice type) are irradiated, a non-monotonic change in the hysteresis parameters is observed – an increase and subsequent decrease in saturation magnetization and a change in coercive force. In samples based on the other two types of NW, the effect of irradiation is ambiguous. Irradiation leads to a strong change in the shape of the tips of Co-NWs.
Keywords:matrix synthesis, metallic nanowires, ion irradiation, radiation damage, electron microscopy, X-ray phase analysis, saturation magnetization, coercive force.
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