Investigation of nanocrystalline iron materials by Mössbauer spectroscopy

Abstract

Nanocrystalline materials, which have been proposed to represent a new solid state structure, are investigated by Mössbauer spectroscopy. Nanocrystalline materials are polycrystals with a crystal size of typically 1–10 nm. These materials consist of two components of comparable volume fractions: a crystalline component and an interfacial component, formed by the atoms located either in the crystals or in the interfacial regions between them. As the atomic configurations of both components are different, two kinds of Mössbauer spectra are expected. Iron nanocrystalline material is found to exhibit a two-component Mössbauer spectrum, consisting of a crystalline component and a second one with different Mössbauer parameters. The Mössbauer parameters of the second subspectrum are consistent with the model of the interfacial component of a nanocrystalline material.