Iron–silicon alloys in the concentration range between 13 and 27 at% Si are investigated using Mössbauer spectroscopy. Such alloys are known to have the D03 crystal structure of ordered Fe3Si which exhibits a wide homogeneity range. Non‐stoichiometric alloys, however, show complicated Mössbauer spectra with many subspectra due to the various Fe sites which in this case are present in the D03 structure. The aim of this investigation is to improve both the spectral resolution of the Mössbauer spectra obtained for various Si concentrations and the assignment of the subspectra to the Fe sites. Using appropriate binomial distributions, it would then be possible to calculate the silicon content of the alloys from the Mössbauer spectra.

An unstable fcc-Fe50Cu50 alloy has been prepared by milling of elemental powder blends. The structure and the decomposition behavior of the alloy were studied by x-ray diffraction and Mössbauer spectroscopy. A broad distribution of different local environments of the iron atoms was observed in the fcc-FeCu phase. This indicates that Fe and Cu are mixed on an atomic level. In the initial state of decomposition, iron atoms precipitated coherently in the fcc-FeCu matrix as fcc-Fe particles. At higher annealing temperatures the particle size increased during the thermal treatment, and the fcc-Fe precipitates transformed into the bcc-Fe structure.

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The counting rate of the 88 keV Ag109m γ-rays emitted from a cd109-doped silver single crystal was measured as a function of temperature. The decrease in emission intensity between 78 K and 4.2 K was greater than the decrease between room temperature and 78 K. This behaviour is explained in terms of the temperature dependence of the resonant self absorption (Mössbauer effect)