| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a new ferrite particle suitable for high-density magnetic recording. <P>SOLUTION: The ferrite particle for a magnetic recording medium has an M type ferrite structure, a rare earth element R containing Ca, La essentially, and Sr, Fe and Co as essential elements and has the composition shown by the formula: Ca<SB>1-x-y</SB>R<SB>x</SB>Sr<SB>y</SB>Fe<SB>2n-z</SB>Co<SB>z</SB>(wherein (1-x-y) is the content of Ca and 0.3≤(1-x-y)≤0.65; x is the content of the rare earth element R and 0.2≤x≤0.65; y is the content of Sr and 0.001≤y≤0.2; z is the content of Co and 0.03≤z≤0.65; n is a molar ratio and 4≤n≤7; (1-x-y)>y, (1-x-y)>z>y, x>z>y are satisfied). <P>COPYRIGHT: (C)2010,JPO&INPIT |
