A NEW METHOD OF PREPARING W-TYPE HEXAGONAL FERRITES

摘要

A process for preparing W-type hexagonal ferrites of the formula Ae2+Me2+2Fe3+16O27 where Ae is an alkaline earth metal such as Ba, Sr, or Pb or a partial replacement with trivalent and monovalent metals thereof and Me is a divalent metallic ion such as Fe Zn, Cu, Ni, Mn, Mg, or a combination of these divalent metals or a partial replacement with trivalent and monovalent metals thereof, comprising: taking commercially available pure chemical ingredients of the said formula in the ratio of Ae2+ to Me2+ and Fe3+ as 1:18, mixing the said chemical ingredients by ball-milling process and forming pellets by pressing, calcining the said pellets between 950°C - 1000°C and quenching from calcination temperature to liquid nitrogen temperature to avoid the formation of S and M phases separately, ball-milling the quenched material and forming pellets by using an organic binder and a sintering aid, sintering the said pellets between 1250° C - 1300° C and again quenching from the sintering temperature to liquid nitrogen temperature to get W-type ferrite.