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

Physica Status Solidi (A) Applications and Materials. 2021. Vol. 219. No. 3. Article 2100538.

Panina L., Dmitri L. Zagorskiy, Shymskaya A., Ilia M. Doludenko, Evstigneeva S., Melnikova P., Khairetdinova D., Lukkareva S., Gilimyanova A.

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 magne-
toresistance. 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 briefl y overviewed.

Keywords: трековые мембраны, матричный синтез, matrix synthesis, Magnetic nanowires, магнитные нанопроволоки, Track etched membranes