Magnetic and structural properties of the mechanically alloyed Nd-2(Fe100-xNbx)(14)B system

摘要

=In this work we report the magnetic and structural properties obtained by Mossbauer spectrometry, Vibrating Sample Magnetometer and X-ray diffraction of milled powders with initial composition Nd-2(Fe100-xNbx)(14)B with x = 0 and x = 4. The mixtures were ball milled for different times up to 240 h. Structural and microstructural parameters were derived from high statistics X-ray patterns and discussed as a function of milling time. The Mossbauer spectra of the samples were fitted by means of a sextet and an hyperfine field distribution, associated to a pure iron phase (alpha-Fe) and a disordered iron-based phase, respectively. The alpha-Fe grain size decreases from 50 nm for 6 h up to 5 nm for 240 h milling time. The Vibrating Sample Magnetometer results allow to conclude that these samples behave as soft ferromagnets.