Magnetic Properties of Alumina-carbon Nanotube Nanocomposites Mediated by Iron Catalysts

Alumina oxide (Al₂O₃) is an important ceramics insulator and carbon nanotubes (CNTs) have intriguing mechanical, thermal, electrical, and magnetic properties. We report the synthesis of CNTs - Al₂O₃ nanocomposites using chemical vapor deposition (CVD) process utilizing iron as the catalyst. The structures and morphologies of the as-prepared samples were characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffractometer (XRD), thermogravimetric analyzer (TGA), and Mössbauer spectroscopy. The experimental results show that these as-synthesized composites contain CNTs of average diameter of 40 nm distributed homogenously within the alumina matrix. The percentage of CNTs within the composites is around 7%. Magnetic properties of the samples were measured using vibrating sample magnetization at room temperature and under cryogenic conditions. Such characterization is necessary for the synthesis of magnetic nanocomposites with potential for applications in various materials.

Keywords: carbon nanotubes, alumina, magnetic hysteresis, field-cooled-magnetization