Microstructure and characterization of W-type hexaferrite Ba_(1-x)La_xFe_2~(2+)Fe_(16)~(3+)O_(27) prepared by solid state method

摘要

We report a successful preparation of Ba1-xLaxFe22+Fe163+O27 (x = 0.00-0.10) W-type hexagonal ferrites by standard ceramic method in a reduced oxygen atmosphere. In this work, the effect of the substitution La3+ rare-earth ions for Ba2+ ions on the structural and magnetic properties of the prepared samples have been studied. The phase identification of magnetic powders was performed by X-ray diffraction. The results of XRD show that the single phase was observed in the W-type ferrites with different La content. The SEM micrographs showed that the ferrites have formed the hexagonal structure. The magnetic properties of the samples were metric by a vibrating sample magnetometer. The coercivity (H-c) of the particles decreases with the increase of La content(x), while the saturation magnetization (M-s) of the particles first increases with x from 0 to 0.05, and then begins to decrease when x continues to increase. The monotonic dependence of the magnetic anisotropy field H-a and coercivity H-c on the La3+ doping amount is found to be mainly dominated by the competition between M-s and K-eff. (C) 2018 Elsevier B.V. All rights reserved.