On the nature of the magnetostructural phase transition in Ce(Fe1-xSix)2

Abstract

To ascertain the nature of the magnetostructural phase transition in Ce(Fe1-xSix)2 compounds with low silicon content, which crystalize into the structure of cubic Laves phase, we studied local structure peculiarities using high-precision 57Fe Mössbauer spectroscopy (with a high discretization of the velocity reference signal). Unlike the earlier published works on this type of compounds, in the study presented, the occurrence of at least two different types of local surrounding of Fe atoms in the binary compound CeFe2 and non-random Si distribution in the Ce(Fe1-xSix)2 crystal structure is reported for the first time. To specify the type of ordering of Si atoms, the experimental data are compared with results of mathematical simulation of different types of ordering, and, in this way, a conclusion on the mechanism of magnetostructural phase transition is made.