Magnetic properties of multi-walled carbon nanotubes encapsulated
Fe/Co particles
Fe/Co particles
(1. Department of Physics, Lanzhou University of Technology, Lanzhou 730050, China;
2. Gansu Key Laboratory of New Nonferrous Metal Materials, Lanzhou University of Science and Technology,
Lanzhou 730050, China)
2. Gansu Key Laboratory of New Nonferrous Metal Materials, Lanzhou University of Science and Technology,
Lanzhou 730050, China)
Abstract: The experimental apparatus by self-designed was used, Fe/Co particles encapsulated in multi-walled carbon nanotubes (MWCNTs) were prepared by the method of anodic arc discharging plasma. The products were characterized by transmission election microscopy, Raman spectroscopy and X-ray diffractometry. The magnetic properties of the products were characterized with vibration sample magnetometer. The TEM results show that MWCNTs have little impurity and good particles size, and Fe/Co with high continuity encapsulaties in carbon nanotubes. The saturated magnetization (σs), remanence (σm) and coercivity (Hc) of the sample are 17.30 A/(m·kg), 3.96 A/(m·kg) and 31 521.60 A/m, showing better ferromagnetism compared with the bulk Fe/Co. The optimal conditions in this case are as follows: a helium gas atmosphere of 6.0×104 Pa, an arc current of 70 A, a voltage drop of 24 V, a constant distance of about 2 mm between the anodes and cathode, metallic powder contents of Fe and Co of 15.0% (mass fraction) and 15.0%, respectively, and well cooled electrodes and collector. This process is a convenient and effective that Fe/Co particles can be encapsulated in MWCNTs.
Key words: multi-walled carbon nanotubes; Fe/Co particles; anodic arc; magnetic properties