| 摘要 |
<p>The present invention relates to improved cobalt-substituted gamma -ferric oxide magnetic powder suitable for application in magnetic recording. Said powder comprises a batch composition which is characterized by addition of controlled amounts of at least one compound selected from the group of NH4, Cu, Li, Pb, Sn, Ba, Cd, Sr and In halide compounds to the mixture of acicular powder of goethite with a controlled amount of cobalt compound, said batch composition being mixed, heated at a temperature from 300 DEG to 600 DEG C in a reducing gas atmosphere, and finally oxidized at a temperature from 150 DEG C to 350 DEG C in air or oxygen gas atmosphere.</p> |
