Two- and three-component alloys nanowires: correlation of structural and magnetic properties

Abstract

Several types of nanowires (NWs) made of alloys of various compositions obtained by the method of matrix synthesis based on track membranes have been studied. Electrolytes were selected to obtain NWs of the desired composition. The control of electrodeposition by chronoamperograms made it possible to systematically change the geometric parameters and morphology. The topographies of the resulting NW arrays and their elemental composition were studied using electron microscopy with an X-ray spectral analyzer. The magnetic properties of the samples were studied on a vibrating magnetometer. The structures of binary alloys were studied: for NWs of FeCo alloys, the dependence of the coercive force on the composition was studied. The obtained dependence has two maxima --- at an equiatomic composition and at a cobalt content of about 90%. For Fe0.3Co0.7 NWs, a sharp increase in the coercive force with decreasing diameter is shown. It is assumed that this effect is due to the formation of single-domain crystallites, the processes of magnetization reversal of which are associated with a uniform rotation of the magnetization. For NWs made of FeNi alloys, the influence of the aspect ratio on the coercive force has been proved. Ternary alloys of the FeCoCu system have been studied: it has been shown that the addition of copper significantly increases the coercive force, which reaches a maximum at a copper content of about 5%. The obtained X-ray data suggest that the effect of an increase in the coercive force is associated with the formation of fine-grained inclusions based on copper, which lead to effective deceleration of the domain walls. The data obtained expand the range of possibilities for controlling the magnetic properties of NW arrays obtained by the method of matrix synthesis. Keywords: nanowires, matrix synthesis, microscopy, elemental analysis, magnetic properties, coercive force. Keywords: nanowires, matrix synthesis, microscopy, elemental analysis, magnetic properties, coercive force.