MOSSBAUER STUDY OF THE STABILITY OF FE5SI95 PRODUCED BY INERT-GAS CONDENSATION

Fe5Si95 specimens with an enhanced solubility of Fe in Si by about twenty-one orders of magnitude relative to crystalline Si at room temperature were prepared by the inert gas condensation technique. The thermal stability of the Fe5Si95 sample was investigated by Mossbauer spectroscopy. The spectrum of the as-prepared Fe5Si95 exhibited a broadened many different iron sites in the sample. This material was thermal stable up to temperature of 673K for one hour. After annealing at 773K for one hour, the intermetallic compound alpha-FeSi2 was formed in the annealed sample, probably via the precipitation process. The amount of the alpha-FeSi2 phase increased with the annealing temperature. No beta-FeSi2 phase was observes in any of the annealed samples up to an annealing temperature of 1273K For one hour.