Ferromagnetic carbon-coated iron and its compounds nanocrystallite synthesized at high metal to carbon rate and high yield by a modified AC arc method

Ferromagnetic carbon-coated iron and its compounds nanocrystallite had been synthesized efficiently at high metal to carbon rate (up to 80 wt.%) and high yield (95%) by a new modified AC arc discharge. The mental to carbon rate of the particles could be controlled by the pressure of the buffer gas. The morphology and structure of the carbon coating and materials enclosure were examined by high-resolution transmission electron microscopy (HRTEM) and X-ray diffractometer. The metal to carbon rate of the particles was determined by thermogravometric analysis (TG). The magnetic properties of these particles were measured with a vibrating sample magnetometer. Typical sizes of these particles were 10–30 nm. The metal to carbon rate ranged from 73.5 to 80.5 wt.% as the pressure of the He atmosphere charging from 0.06 to 0.01 MPa. The Br, Bs and Hc of particles made at the buffer gas pressure of 0.01 MPa with a metal to carbon rate of 80 wt.% were 455.7 G, 3405 G and 219.4 Oe, respectively.