Structure and Magnetic Properties of Layered Nanowires of 3d-Metals, Fabricated by the Matrix Synthesis Method

Abstract

Based on PET track etched membranes, arrays of layer nanowires 100 nm in diameter, consisting of alternating Ni/Cu and Co/Cu layers are grown by the matrix synthesis method. Galvanic deposition processes are studied and conditions for fabricating layer nanowires with different thicknesses for magnetic (Ni or Co) and nonmagnetic (Cu) layer components are determined. An electron microscopic study is performed to verify conditions for fabricating layer nanowires and to correct geometrical sizes of alternating layers. Magnetization curves of produced arrays of layer nanowires are measured by vibration magnetometry methods at room temperature for two extreme orientations of a scanning magnetic field, i.e., parallel and perpendicular ones with respect to the nanowire growth axis. It is shown that the magnetic anisotropy of the nanowire array is controlled not only by the chemical composition, but also the thickness and alternation period of magnetic metal layers in nanowires. The dependence of the magnetostatic energy and demagnetizing field in the synthesized layer nanowires on the magnetic metal filling factor is numerically evaluated; the results are in qualitative agreement with experimental observations.