Abstract
The one-step synthesis of ceramic coated magnetic metal nanoparticles is described using a radio-frequency (RF) thermal plasma. Phase compositions of the obtained nanoparticles were characterized by X-ray diffraction and shapes and size of the synthesized particles were analyzed by an electron microscope. Additionally, elements analysis of the coated particles was performed by energy dispersive spectroscopy. The phase composition of the prepared particles was mainly composed of amorphous ceramics and magnetic metal. It was confirmed that the magnetic metal particles was coated by ceramics. Furthermore, the mechanism of the formation of ceramic coated metal in the plasma was predicted. The obtained FeCo-Al2O3 core-shell nanoparticles have a magnetic value of 1.96×10-3 A･m2 / g and a coercivity of 46.2 kA / m. This method based on RF thermal plasma is advantageous over previous methods in suitability for large-scale production and the synthesized ceramic coated magnetic metal nanoparticles have wide applications in many fields.
