Preparation and characterization of LaFe12O19 hexaferrite

Three different methods (mechanical alloying, coprecipitation and sol-gel) were used for preparing LaFe12O19 hexaferrite and all seem to be suitable for preparation of this phase. A heat treatment in the small temperature range between 1360 and 1390 degrees C followed by a rapid quenching is necessary for all preparation methods, since without quenching it is not possible to preserve the La-hexaferrite phase. Detailed investigations were performed for the method of coprecipitation varying the La excess, the heat treatment temperature and the quenching method. (c) 2004 Elsevier B.V. All rights reserved.