| 摘要 |
PURPOSE:To provide an industrially advantageous manufacture of magnetic oxide iron powder containing cobalt. CONSTITUTION:Oxide iron powder is obtained by directly reducing, as a precursor, gamma-FeOOH, whose surface is covered with an Al oxide or reducing it after heating it at a temperature lower than the temperature where it transits to hematite and dehydrating it, or oxidizing it further after reduction, and magnetic iron powder containing cobalt, which fulfills the following formulae (1) and (2) by covering the surface with a cobalt compound or a cobalt compound and other metal compound. But, BET specified surface area (m<2>/g):. Formula (1): 20<=SSA<=50, Formula (2): -16.70<=log [V]<=-3.05log [SSA] -11.35. |
