| 摘要 |
PURPOSE:To obtain magnetic powder having a designated coersive force, high degree of saturated magnetization and excellent vertically magnetized orientational property of high dispersibility by a method wherein the specific quantity of a bivalent metal element is allowed to be present when a sintering operation and a barium ferrite precursor growing process are performed. CONSTITUTION:A barium ferrite precursor is obtained by conducting a heat treatment at 60-250 deg.C on the alkaline suspension having pH of 11 or more and containing the metal element of the molar ratio of 1/6>=Ba/Fe+M1+ M2>=1/12 (M1 indicates a kind selected from a group of Co, Ni, Zn, Cu, Mg and Mn, and M2 indicates a kind selected from a group of Ti, Sn, Zr, Ge, Nb and V), the molar ratio of M2 is 0.01-0.2 against Fe of 1, and M2 is 0-0.5 against M1. The metal element compound M2 or M1 and M2 is added to said precursor in such a manner that the total amount of M1 and M2 becomes 0.3 mol or less against 1 mol of M2 or M1, M2 and Fe, then they are sintered at 650-1000 deg.C, and barium ferrite crystal grains are obtained. |
