Structure and Magnetic Properties of Nanocrystalline Fe-Mo Alloys Prepared by Mechanosynthesis

Nanocrystalline samples of Fe$\text{}_{80}$Mo$\text{}_{20}$ and Fe$\text{}_{50}$Mo$\text{}_{50}$ alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X-ray diffraction. The magnetic properties of the milled products were determined by the M"ossbauer spectroscopy. It was observed that in the case of the Fe$\text{}_{80}$Mo$\text{}_{20}$ alloy a solid solution of Mo in Fe was formed with the lattice parameters of Fe increasing from 0.28659 nm to 0.29240 nm and the crystallite size decreasing from 250 nm to 20 nm. In the case of the Fe$\text{}_{50}$Mo$\text{}_{50}$ alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the milling process, but the crystallite size decreased from 200 nm to 15 nm. Mössbauer spectra revealed different magnetic phases in the mechanosynthesized Fe-Mo samples. In the case of the Fe$\text{}_{80}$Mo$\text{}_{20}$ alloy, the spectrum for the milled mixture indicated the formation of a solid solution. In contrast, for the Fe$\text{}_{50}$Mo$\text{}_{50}$ the spectrum indicated the disappearance of the ferromagnetic phase.