COATED MAGNETITE PARTICLE

摘要

PROBLEM TO BE SOLVED: To provide a coated magnetite particle manufactured by uniformly coating a surface of a core particle of magnetite with an alkylsilane compound.SOLUTION: There is provided a coated magnetite particle having an alkylsilane compound layer on a surface of a core particle of magnetite. A part of iron in the core particle of magnetite is substituted with manganese. An amount of manganese eluted when the core particle of magnetite is melt by 10 mass% from a surface in an iron element basis is 0.05 mass% to 0.35 mass% to the whole core particle.