$\mathrm{Fe}_{1-x}\mathrm{Ni}_x$ Alloy Nanoparticles Encapsulated inside Carbon Nanotubes: Controlled Synthesis, Structure and Magnetic Properties

TL;DR

This study demonstrates controlled synthesis of $ ext{Fe}_{1-x} ext{Ni}_x$ alloy nanoparticles inside carbon nanotubes, analyzing their structure and magnetic properties, revealing enhanced coercivity suitable for magnetic storage applications.

Contribution

It introduces a method to encapsulate and tailor $ ext{Fe}_{1-x} ext{Ni}_x$ nanoparticles within CNTs, controlling their size, composition, and magnetic properties.

Findings

Enhanced coercive fields compared to bulk materials.

Successful encapsulation and control over nanoparticle size and composition.

Potential for use in magnetic storage devices.

Abstract

In the present work, different synthesis procedures have been demonstrated to fill carbon nanotubes (CNTs) with $\mathrm{Fe}_{1-x}\mathrm{Ni}_x$ alloy nanoparticles (x = 0.33, 0.5). CNTs act as templates for the encapsulation of magnetic nanoparticles, and provide a protective shield against oxidation as well as prevent nanoparticles agglomeration. By variation of the reaction parameters, the purity of the samples, degree of filling, the composition and size of filling nanoparticles have been tailored and therefore the magnetic properties. The samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Bright-field (BF) TEM tomography, X-ray powder diffraction, superconducting quantum interference device (SQUID) and thermogravimetric analysis (TGA). The Fe1-xNix-filled CNTs show a huge enhancement in the coercive fields compared to the corresponding bulk materials, which make them excellent candidates for several applications such as magnetic storage devices.