PREPARATION OF ULTRAFINE GAMMA-FE PARTICLES BY MICROWAVE PLASMA PROCESSING

Ultrafine γ-Fe particles were produced by processing α-Fe particles which were prepared by the gas evaporation method. The processing was achieved by passing the α-Fe particles through a microwave plasma and then quenching them. The processed iron particles are found to consist of the high temperature γ phase (fcc) and the low temperature α phase (bcc). The abundance of γ phase particles depends on the microwave power, Ar gas pressure and the gas velocity in the plasma region. Effects of the plasma processing on the quenching of the γ phase are discussed on the basis of the gas temperature measurement. © 1990.