Structure and Magnetic Properties of CNT-Reinforced Iron Composites

TL;DR

This study explores how adding carbon nanotubes to iron affects its structure and magnetic properties, showing improved magnetization.

Contribution

The novel contribution is demonstrating that CNTs can enhance the magnetic properties of iron composites.

Findings

CNTs retained their nanostructure after ball milling despite some damage.

Higher CNT content increased grain size and lattice strain in iron.

Fe-CNT composites showed higher saturation magnetization and lower coercivity than pure iron.

Abstract

Fe-CNT composites were synthesized via mechanical ball milling, incorporating varying amounts of carbon nanotubes (CNTs) into iron powder at concentrations of 1 wt%, 2 wt%, and 3 wt%. The impact of different CNT contents on the phase structure, microstructure, and magnetic properties of the composites was examined. Raman spectroscopy and X-ray diffraction (XRD) analyses revealed that despite some damage, CNTs retained a predominantly one-dimensional nanostructure post-ball milling. Moreover, an increase in CNT content led to a gradual rise in grain size and lattice strain of the iron powder, attributed to the formation of solid solutions and iron–carbon compounds. Scanning electron microscopy (SEM) observations demonstrated that the majority of CNTs were integrated within the iron matrix particles, with a minority either partially embedded or entirely unembedded on the iron powder surface. With higher CNT concentrations, local CNT agglomeration emerged and intensified. Vibrating sample magnetometer (VSM) measurements indicated that Fe-CNT composites exhibited enhanced saturation magnetization (2.25%) and reduced coercivity (91.74%) compared to pure iron, underscoring the potential of CNTs in enhancing the magnetic properties of iron powder.

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