PREPARATION, INFRARED SPECTROSCOPY, AND PHASE STABILITY OF NANOSIZED IRON SILIClDE POWDERS

摘要

Nanosized powders of iron silicides were prepared by the arc plasma method. These silicide powders were characterized by X-ray diffraction and transmis- sion electron microscopy. The lattice vibrations of nanosized E-FeSi were investigated by Fourier-transformation infrared spectroscopy and compared with those of bulk FeSi. To determine the stability of different iron silicides, powder mixtures of E-FeSi and a-FeSi_2 were treated thermally in different atmospheres, and at high pressure as well. The different behaviors of a-FeSi_2 could be understood by means of the thermodynamics and kinetics of,struc- tural transformation in nanosized a-FeSi_2 grains.