Magnetic powder, manufacturing method of magnetic powder, and magnetic recording medium

A manufacturing method of magnetic powder formed of at least one epsilon-phase iron oxide-based compound selected from the group consisting of ε-Fe2O3 and a compound represented by Formula (1),

• ε−AaFe2-aO3 (1)
• wherein, in Formula (1), A represents at least one metal element other than Fe, and a represents a number that satisfies a relationship of 0<a<2,
• the method comprising:
• mixing an aqueous solution of a compound including a trivalent iron ion as a raw material of magnetic powder, with an alkali agent, to obtain a mixed solution I;
• mixing the mixed solution I with a polyvalent carboxylic acid aqueous solution to obtain a mixed solution II, stirring the mixed solution II, and separating a solid component from the mixed solution II after the stirring;
• re-dispersing the solid component in a dispersion medium including water, adding an alkali agent, and adding a silyl compound including a hydrolyzable group, to obtain a dispersion liquid;
• incorporating a component capable of aggregating the solid component by salting out into the dispersion liquid, and separating a generated precipitate, to obtain a magnetic powder precursor;
• subjecting the magnetic powder precursor to heat treatment at a temperature condition of 800° C. to 1,400° C.;
• and
• removing a silicic acid compound in the heat-treated magnetic powder precursor by using an alkali aqueous solution.