Magnetic properties of multi-walled carbon nanotubes encapsulated Fe/Co particles

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 （σ5）, remanence （σm） and coercivity （He） 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 6.0×10^4 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.