Hollow nickel microspheres covered with oriented carbon nanotubes and its magnetic property

A composite structure consisting of hollow nickel microspheres coated with oriented carbon nanotubes (CNTs) was synthesized via chemical vapor deposition at 800 °C. The hollow microspheres were composed of discrete Ni nanoparticles which acted as the catalyst. FESEM images showed that the CNTs grew on the surface of the Ni spheres. HRTEM, Raman and XRD analyses showed that the CNTs were highly graphitized. Magnetic measurements demonstrated that these composite structures exhibited enhanced ferromagnetic behaviour compared with hollow Ni spheres and bulk Ni.