Sodium ferrite particle powder and production method thereof

A sodium ferrite particle powder, wherein at least one metal or more selected from the metal group consisting of silicon, aluminum, titanium, manganese, cobalt, nickel, magnesium, copper and zinc is contained in an amount of 0.05 to 20% by weight in terms of the oxide, and a molar ratio of Na/Fe is 0.75 to 1.25, wherein an average diameter of primary particles of the sodium ferrite particle powder is 50 to 1000 nm, wherein an axial ratio of an average major axis diameter to an average minor axis diameter of the primary particles is 1 to 2.

A sodium ferrite particle powder, wherein at least one metal or more selected from the metal group consisting of silicon, aluminum, titanium, manganese, cobalt, nickel, magnesium, copper and zinc is contained in an amount of 0.05 to 20% by weight in terms of the oxide, and a molar ratio of Na/Fe is 0.75 to 1.25, wherein an average diameter of primary particles of the sodium ferrite particle powder is 50 to 1000 nm, wherein a pH value of the sodium ferrite particle powder is 8 to 14.