| The formation of W-type Ba(Me)2Fe16O27 (Me=Zn, Ni) hexaferrites were studied by synthetizing them, using Fe2O3, ZnO, NiCO3 and BaCO3 as starting materials. The synthesis was made in numerous steps. At first some of the starting materials were premilled by high-energy milling (HEM) (Fritsch Pulverisette 4) in different combinations to promote the formation of solid solutions involving the substitution of one divalent cation by another, or by a combination of divalent cations. In the next step presintering of the materials was carried out. After that the material was again milled by HEM using different milling parameters then compacted and sintered. TG-DTA examinations of the outgoing materials and variously prepared milled products were made to reveal the differences in the solid-state reactions, and XRD, SEM, TEM measurements, in order to observe the changes in the crystalline structure, morphology and composition. By the applied procedures good quality W-type Ba-hexaferrite could be observed. |
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