SWITCHING FIELD DISTRIBUTION CHANGES DURING REACTION-MILLING OF IRON-ZINC NANOCOMPOSITES

DC remanent hysteresis loops have been measured for a series of reacti on-milled Fe-Zn nanocomposites, The remanence curves are characteristi c of the amount of the material switched into the field direction in a given field, The derivative of the remanence curve, the SFDR, is dire ctly related to the distribution of the size and shape of particles. F or the relatively homogenous starting powder of Fe3O4, SFDR=0.77, it i s increasing to a very large value during the actual chemical reaction (after 2 hrs of milling), and it is decreasing to 1.00 after 9 hrs of milling, indicating that the resulting Fe particles have a wider size and shape distribution than the original powder, The change in SFDR c an be used as a quick tool for characterizing the magnetic particles i n the nanocomposite.