| 摘要 |
PROBLEM TO BE SOLVED: To provide iron-based oxide magnetic particle powder suitable for achieving a higher recording density with respect to a magnetic recording medium, in which the particle size distribution is narrow, the content of microparticles that do not contribute to magnetic recording characteristics is small, and, as a result, the coercivity distribution is narrow, and a method for producing iron-based oxide magnetic particle powder.SOLUTION: An ε-type iron-based oxide magnetic particle powder containing a substituted metal element can be obtained by: adding alkali to an aqueous solution containing trivalent iron ions and metal ions partially substituting Fe sites and neutralizing the pH to a pH of 1.5 or more and 2.5 or less; thereafter adding hydroxycarboxylic acid, and further adding alkali to neutralize the pH to a pH of 8.0 or more and 9.0 or less; washing a generated precipitate of iron oxyhydroxide containing a substituted metal element; and thereafter covering the iron oxyhydroxide containing the substituted metal element with silicon oxide and heating the same.SELECTED DRAWING: Figure 3 |
