1D Nanomaterials in Fe‐Group Metals Obtained by Synthesis in the Pores of Polymer Templates: Correlation of Structure, Magnetic, and Transport Properties

Abstract

1D cylindrical magnetic nanostructures (FeNi, FeCo, FeCoP) of complex topology such as nanowires (NWs), nanotubes (NTs), multilayered nanowires, and core–shell structures are discussed from the perspective of engineering a wide variety of magnetic materials from hard to semihard to soft. Most of recent data are given for the materials synthesized in the pores of polymer ion‐track membranes, which makes it possible to tune systematically the geometrical parameters, morphology, and composition. The key properties including crystal and micromagnetic structure, magnetic anisotropy, and coercivity are analyzed. Co‐based NWs with uniform morphology demonstrate coercivity of more than 10 kOe due to the combination of crystalline and shape anisotropies. In the case of NTs, the demagnetizing effect is reduced owing to a helical arrangement of the magnetization, which leads to low values of coercivity and remanence magnetization. Varying the geometrical parameters of multilayered NWs, the alternating soft and semihard magnetic layers can be made within a single nanowire, which is important for spin‐valve magnetoresistance. Au‐coated ferromagnetic nanostructures are biocompatible and can be used to enhance optical absorption. Ni@Au NTs used as substrates for Raman spectroscopy demonstrate the enhancement factor of the order of 104. Some aspects related to applications of 1D magnets are briefly overviewed.

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

“…Note that the same trend was observed in iron-nickel NW [19]. However, in these cases, there is a different orientation: for FeNi-NW, the H c values were larger for a field applied perpendicular to the NW axis.…”

“…The study of dependence of magnetic properties of FeCo-NW samples on their composition [19] has begun. The non-linear nature of this relationship is shown: a basic maximum of H c is found for samples with equiatomic composition (as well as for bulk samples).…”

Нанопроволоки Из Двух- И Трехкомпонентных Сплавов: Корреляция Структурных И Магнитных Свойств

“…Начато изучение зависимости магнитных свойств образцов FeCo-НП от их состава [19]. Показан нелинейный характер этой зависимости: основной максимум H c обнаружен для образцов с эквиатомным составом (так же, как и для объемных образцов).…”

Ion-Track Template Synthesis and Characterization of ZnSeO3 Nanocrystals

“…Among these experiments, the targeted use of ion irradiation to form new nanostructured materials such as nanoclusters and nanowires should be noted, which have received particularly great attention in the last twenty years due to their special physical properties and new applications [21,22]. It is important to mention here that the so-called ion-track template synthesis is one of the simplest and most inexpensive methods for obtaining metal and semiconductor nanoclusters and nanowires [23][24][25][26][27][28][29][30][31][32][33]. The "ion-track etching" technique is a quite industrial method that can be used to create nanoscale pores in a range of different materials, including polymers, semiconductors, and dielectrics.…”