The structure of layered Cu/Ni nanowires obtained by template synthesis in 100-nm channels of track membranes has been investigated by transmission and scanning electron microscopy. The phase...

The processes of formation of one-dimensional nanostructures by the method of matrix synthesis was studied in this work. Nanowires (NWs) from magnetic metals of iron-group and copper (3-d metals) were synthesized in the pores of matrix-track membranes by galvanic deposition. NWs with both homogeneous elemental distribution (alloys) and with periodically alternating parts with different composition (layers) were obtained in matrices with different pore diameters and under different parameters of the galvanic process. The transport of ions, which determined the growth of wires, in pores of different sizes was analyzed. The influence of the size of pore channels on the features of NWs growth, the correlation between the elemental composition of the NWs and the growth electrolyte, as well as the influence of the growth conditions (voltage and pore diameter) were investigated. Approaches to formation of thin layers in layered NWs were studied. This included the choice of methods for controlling the pulse duration, slowing down the growth rate by the dilution of the solution, the use of additives and the work with reference electrode. The study of NWs was carried out using visualization and analysis of their structure using transmission and scanning electron microscopy, electron diffraction, energy dispersive analysis, and elemental mapping. For the studied types of samples, a relationship was established between the growth conditions and the structure. This data raises the possibility of varying the magnetic properties of NWs.

A problem of fabrication of magnetic polymer capsules for targeted drug delivery is considered. Magnetic nanoparticles are used in the problem under study. A method for fabrication of such particles involving synthesis of layered nanowires with alternating layers of the specified magnetic metal and sacrificial layers of nonmagnetic metal is proposed. A method for template-assisted synthesis based on ac-potential electroplating of specified metals in the pores of track membranes is used to fabricate wires with a diameter of 100 nm with nickel layers of 400 and 200 nm. A method for the subsequent extraction of nickel fragments using selective etching (removal) of copper fragments is developed. Procedures that prevent aggregation of magnetic nanoparticles and penetration of the nanoparticles in the shells of polymer capsules are considered.

A method for the formation of magneto-optical one-dimensional (1-D) nanostructures by the electrodeposition method into the pores of track-etched membranes is presented in this letter. Two possible techniques are considered: the synthesis of magnetic nanotubes and their subsequent coating with silver, as well as the synthesis of vertical-standing arrays of layered magneto-optical nanowires (NWs) with alternating layers of nickel and silver. The resulting nanotubes and NWs are polycrystalline microstructures with a nanostructured plasmon-active surface. The absorption spectra have a distinct peak corresponding to the position of the local plasmon resonance: in the near-infrared range for the nickel nanotubes coated with silver and in the optical range for the layered NWs. For layered NWs, there is a combination of absorption peaks of both silver and nickel. The use of the obtained 1-D magneto-optical nanostructures for the formation of plasmon-active magnetically controlled substrates as surface-enhanced Raman spectroscopy (SERS) active surfaces is suggested for the detection of Rhodamine 6G in concentration down to 10 ^–9 M. The increase of SERS signal intensity by using a magnetic field is shown for concentration 10 ⁻³ M with an extra signal amplification of more than four times.

Heterostructural nanowires with alternating layers of copper and nickel are obtained by matrix synthesis and then cut into cylindrical magnetic nanoparticl

The paper considers the specific features of obtaining metal nanowires by matrix synthesis based on track membranes. The first part of the work considers the main ideas of the method and reviews the published sources devoted to producing nanowires of various types—single-component (from one metal) and multicomponent (from two or several metals). Variants of obtaining homogeneous structures (so-called alloyed nanowires) and heterogeneous structures (so-called layered nanowires) are considered for the latter case. A series of specific features of the electrodeposition method in the case of carrying out the process in a limited volume of membrane pores is considered. The second part of the work considers the experimental results obtained by the authors upon studying the electrodeposition of nanowires made of an iron–nickel alloy. The aim is to find a relationship between the conditions of the synthesis of nanowires and their structure and elemental composition. The features of the electrodeposition of nanowires are investigated and their topography is studied by electron microscopy (with elemental analysis); X-ray method is applied for studying the structure. So-called abnormal electrodeposition of iron is detected. The dependence of the integral elemental composition of the obtained nanowires on the pore diameter and growth voltage is discussed. Data on the nature of distribution of elements along the length of the nanowires are obtained; it is shown that the nonuniformity of the composition is determined by the conditions of production (in particular, different diffusion mobilities of ions in narrow pore channels) as well as depends on the voltage and diameter of the pore channels. Based on the X-ray diffraction data, the type of the lattice (FCC) is determined, and the nature of the change in the lattice parameter is shown which is presumably associated with the difference in the ionic radii of metals.