| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hexagonal ferrite particle powder for a magnetic recording medium capable of reducing noise of the magnetic recording medium and suppressing degradation of the magnetic recording medium. <P>SOLUTION: Since a hexagonal ferrite particle powder for a recording medium has an average plate surface diameter of 10 to 30 nm and is made of a material represented by general formula of AFe<SB POS="POST">12-x/2-2y/3</SB>Ti<SB POS="POST">x</SB>Al<SB POS="POST">y</SB>O<SB POS="POST">19</SB>(wherein A represents one kind or more of elements selected from the group consisting of Ba, Sr and Ca), a magnetic impurity is hardly produced. A total amount of platinum group elements (ruthenium, rhodium, palladium, osmium, iridium and platinum) included in the hexagonal ferrite particle powder is 10 ppm or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
