Effect of the Type of Inert Gas on the Plasma Dynamic Synthesis of Iron Oxides

The results are presented from experimental studies to determine the effect the type of inert gas (helium, nitrogen, or argon) used in a mixture with oxygen as the gaseous medium of a reactor chamber has on the product of plasma dynamic synthesis in an iron–oxygen system. X-ray diffractometry and scanning electron microscopy are used to establish that the synthesized materials were ultrafine powders consisting mainly of magnetite Fe 3 O 4 with small inclusions of hematite α-Fe 2 O 3 , wustite FeO, and iron Fe. It is found experimentally that the content of magnetite in the product can be as high as 85 wt % during plasma dynamic synthesis in mixtures of N 2 /O 2 and He/O 2 , resulting in the highest specific saturation magnetization (up to 78.3 emu/g).