Evolution of Magnetic Order in Nanocrystalline Fe1xAlx Alloy

Abstract

Over the last few decades, ordered intermetallics based on aluminides of transition metals, particularly iron, have been studied for their potential application as high-temperature structural materials. As a result of their superior physical, chemical, and mechanical qualities, such as low density, strong corrosion and oxidation resistance, and high strength at both room and increased temperatures, FeAl intermetallics are becoming increasingly appealing for materials engineering. The magnetic characteristics of Fe1 -xAlx alloys rapidly change with changes in the structural composition and, therefore, are considered as a function of x. The ball milling operation causes the formation of a solid-state reaction assisted by severe plastic deformation owing to which the crystallite size is lowered, and an unusual and interesting magnetic behavior emerges in the resulting system. 57Fe Mössbauer spectroscopy is used to investigate the evolution of magnetic order in a highenergy ball-milled Fe-Al solid solution. The Mössbauer spectra of the samples demonstrate the existence of both magnetic and paramagnetic components with the magnetic part including three sub-spectral components. In the Mössbauer spectra of Fe-rich samples, the presence of sextets and the high field component in the hyperfine field distribution (HFD) clearly indicates the high magnetic moment, whereas for the composition x  0.6, the presence of sextets indicates the formation of Fe clusters/Fe-rich phases, while the contribution of paramagnetic phases is also clearly visible from HFD for this composition.