Structure and magnetic properties of nanocrystalline Fe-Mo alloys prepared by mechanosynthesis

Abstract

Nanocrystalline samples of Fe8 0 Mo 20 and Fe50 Mo 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 Fe80 Mo 20 alloy a solid solutio n of Mo in Fe was formed with the lattice parameters of Fe increasing from 0.28659 nm to 0.29240 nm and the crystalli te size decreasing from 250 nm to 20 nm. In the case of the Fe50 Mo 50 alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the millin g pro cess, but the crystallite size decreased from 200 nm to 15 nm. M ossbauer spectra revealed different magnetic phases in the mechanosynthesized Fe-Mo samples. In the case of the Fe80 Mo 20 alloy , the spectrum for the milled mi xture indicated the formation of a solid solution. In contrast, for the Fe50 Mo50 the spectrum indicated the disappeara ce of the ferromagnetic phase.