| 摘要 |
PURPOSE:To obtain ferromagnetic powder having excellent square aspect ratio, by forming a double coating layer on the grain surface of oxide system magnetic powder, which layer has a lower layer composed of specified nonmagnetic substance and an upper layer whose main components are cobalt and nickel. CONSTITUTION:On the grain surface of oxide system magnetic powder, a double coating layer of a lower layer and an upper layer is formed. The lower layer is composed of nonmagnetic substance whose main components are aluminum compound and/or silicon compound. The upper layer is composed of magnetic alloy whose main components are cobalt and nickel. Via the lower layer composed of nonmagnetic substance, the upper layer composed of magnetic alloy whose main components are cobalt and nickel is stuck, thereby making a magnetic alloy layer uniform all over the surface of grain. As a result, the powder exhibits high square ratio, and possesses sufficient saturation magnetization and high coercive force. The preferable mode is as follows, the lower layer composed of nonmagnetic substance is set in the range of 0.1-10weight.% with respect to the oxide system magnetic powder, and the upper layer composed of magnetic alloy is set in the range of 5-50weight.% with respect to the oxide magnetic powder. |
