Deformation-induced structural transformations in Si and the initial stage of mechanical alloying of Si and Fe

Abstract

The methods of X ray diffraction, Mössbauer spectroscopy, IR spectroscopy, and laser diffracto metry are employed to study the changes in the structure and phase transformations that accompany mechanical alloying of Si and 57 Fe used in an atomic ratio of 99 : 1. It is established that the process comprises the development of a nanocrystalline state of Si with crystallite sizes smaller than 10 nm; the formation of an amorphous phase of Si at particle surfaces and in near boundary distorted zones of interfaces in Si nanostruc ture; the penetration of 57 Fe atoms along grain boundaries; and the formation of Si-Fe clusters, the local environment of Fe atoms in which is typical of a deformed α FeSi 2 phase, with these clusters being located in the interfaces.

Study of solid state reactions during mechanical alloying of Si–Fe system with first-principles calculation

“…The experimental spectra in [1,2] and the subspectra obtained after MS processing agree well with the calculations of the a-FeSi 2 .…”

“…The X-ray diffraction of early stages of MA shows the existence of the a-FeSi 2 phase in the mechanosynthesized samples [1,2]. The a-FeSi 2 in an ideal, without vacancies, form and its variants with defects have been calculated in this work.…”

“…In Ref. [1] shown is that during initial stages of mechanical alloying (MA) of a small amount of Fe (1 at%) with silicon, iron forms a-FeSi 2 . In Ref.…”

“…This work is devoted to a theoretical study of a-FeSi 2 obtained by mechanical alloying and is inspired by experiments recently conducted in [1,2], where the samples were mechanically alloyed in a ball planetary mill from powders of silicon and iron enriched by 57 Fe, with further annealing. To study the samples authors of [1,2] used the X-ray structural analysis and the Mossbauer spectroscopy.…”

“…To study the samples authors of [1,2] used the X-ray structural analysis and the Mossbauer spectroscopy.…”