HYDROTHERMAL SYNTHESIS OF MAGNETOPLUMBITE TYPE FERRITE

摘要

PURPOSE:To prompt a reaction for forming ferrite in the hydrothermal synthesis of magnetoplumbite type ferrite in alkaline aq. medium and to obtain ferrite having high saturation magnetization by carrying out the reaction in the presence of a specified org. compd. CONSTITUTION:Necessary raw materials for forming magnetoplumbite type ferrite expressed by the formula (wherein M is Ba, Sr, Ca, Pb; n is 3-6; M' is Si, Ta, Sb, Nb, etc.; x is 0.01-0.7) are mixed in a specified proportion. Necessary mat. of alkali for exceeding one equiv. ratio to the amt. of acid radical, or for adjusting the pH of the reaction system to =11 and water are added to the mixture, and an org. compd. selected from alkylbenzene sulfonic acid, lignin sulfonic acid, amine, carboxylic acid, and lecithin, etc. is added to the mixture, and hydrothermal synthesis is executed at =100 deg.C. Thus, magnetoplumbite type ferrite expressed by the formula is obtd.