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

Magnetic powder comprising:

• at least one epsilon-phase iron oxide-based compound selected from the group consisting of ε-Fe2O3 and a compound represented by Formula (1);
• and
• a surface treatment layer including a silane compound having an aromatic ring in a molecule on at least a part of a surface,
• wherein the magnetic powder has an average particle diameter of 8 nm to 20 nm, and
• a content ratio of carbon atoms of the silane compound included in the surface treatment layer to iron atoms of the at least one epsilon-phase iron oxide-based compound selected from the group consisting of ε-Fe2O3 and the compound represented by Formula (1) is 0.05% to 0.5% in terms of the number of atoms,
• 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.

Magnetic powder comprising:

• at least one epsilon-phase iron oxide-based compound selected from the group consisting of ε-Fe2O3 and a compound represented by Formula (1);
• and
• a surface treatment layer including a silane compound on at least a part of a surface, the silane compound including a hydrocarbon group having 3 to 20 carbon atoms directly bonded to a Si atom,
• wherein the magnetic powder has an average particle diameter of 8 nm to 20 nm, and
• a content ratio of carbon atoms of the silane compound included in the surface treatment layer to iron atoms of the at least one epsilon-phase iron oxide-based compound selected from the group consisting of ε-Fe2O3 and the compound represented by Formula (1) is 0.05% to 0.5% in terms of the number of atoms,
• 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.