Geometry dependence of the annealing effect on the magnetic properties of Fe₄₈Co₅₂nanowire arrays

Abstract

Highly ordered Fe48Co52 nanowire arrays with various interpore distances and diameters were fabricated by electrochemical deposition. The change of their magnetic properties after annealing has great dependences on the interpore distance and the wire diameter. The model of the prolate ellipsoid chain modified with the magnetostatic interaction is employed to explain this geometry dependence of the annealing effect. After annealing at 550 °C in H2 atmosphere, good hard magnetic properties (at room temperature, coercivity Hc = 3.89 kOe, squareness Mr/Ms = 0.954; at 78 K, Hc = 4.55 kOe, Mr/Ms = 0.954) were obtained in the arrays with a diameter of about 22 nm and an interpore distance of about 50 nm.