| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of the needle-shaped particulates including Co without twin crystals, wherein the grain diameter is minute and the needle-shape property is excellent and the needle-shaped magnetic particulates including Co have the excellent magnetic characteristics. SOLUTION: The second iron salt solution including Co salt and strong alkaline solution are prepared (SP1), and both solutions are mixed (SP2) and suspension is formed (SP3). The suspension is aged under the Co/Fe ratio and the second iron concentration (SP4) of 0.01 mol/l or more and 0.10 mol/l or less and the needle-shaped Goethite particulates including Co are obtained (SP5). Furthermore, by performing the heat treatment of this needle shaped goethite particulates including Co in the specified atmosphere, the needle shaped magnetic particulates of FeCo ally are obtained. |
