Mössbauer study of the stability of Fe₅Si₉₅ produced by inert gas condensation

Abstract

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 Mössbauer 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 temperatures of 673k for one hour. After annealing at 773K for one hour, the intermetallic compound α-FeSi₂ was formed in the annealed sample, probably via the precipitation process. The amount of the α-FeSi₂ phase increased with the annealing temperature. No β-FeSi₂ phase was observes in any of the annealed samples up to an annealing temperature of 1273K For one hour.