Magnetic properties of carbon nanotubes filled with ferromagnetic metals

► Magnetic property of the Fe-encapsulated carbon nanotubes (CNTs) was examined. ► Chemical vapor deposition using ferrocene as precursor was used for the CNT growth. ► The CNTs were grown on Fe or Pt/Fe bilayer film deposited on substrates. ► The CNTs grown on Pt/Fe layer give higher coercivity than those on of Fe film. ► This is due to arrangement of the easy magnetization axis of Fe-encapsulated CNTs.