Magnetic Property of Carbon Nanotubes Coated with Cobalt

摘要

There has recently been significant interest and speculation about the novel properties and potential application of nanoscale magnetic materials. In this research work, a method of preparing one-dimensional nanoscale composites based on the coating of carbon nanotubes with metal is proposed and demonstrated. This method is simple, inexpensive, highly reproducible, and might be used to prepare a wide variety of one-dimensional nanocomposites by using carbon nanotubes as templates. The carbon nanotubes were prepared by catalytic decompose of benzene using floating transition method at 1100~1200 . Benzene was used as carbon source and iron as catalyst with sulfur. The carbon nanotubes are straight with diameter 30~80nm, internal diameter 10~50nm and length 50~100 m. It has been demonstrated that cobalt could be plated onto the surfaces of carbon nanotubes by electroless plating. A layer of cobalt is formed as nanoparticles on the surface of the carbon nanotube. The coercive force for the carbon nanotubes coated with cobalt is 767.587 Oe, which is much higher than the value of 10 obtained for cobalt microscale particles. It is confirmed that there is enhancement of magnetic coercivity in nanoscale magnetic rods, by comparison with bulk materials. These characteristic magnetic propeerties, resulting from the nanometer size effect, can be used for high-density magnetic recording. Carbon nanotubes coated with a magnetic metal may be useful for microscopic-scale magnetism research and high-density magnetic recording on account of their higher magnetic coercivity.