Magnetic powder, method of producing the same, and magnetic recording medium

A magnetic recording medium, comprising:

• a recording layer that includes particles containing ε-iron oxide including a ε-Fe2O3 crystal,
• wherein the ε-Fe2O3 crystal includes a pure ε-Fe2O3 crystal in which a Fe site is not substituted with another element,
• wherein
• δ/Mrt [nm/mA] satisfies a relationship represented by the following formula (2):
• 2.0≤δ/Mrt≤120.0 (2),
• wherein δ [nm] is an average thickness of the recording layer and Mrt [mA] is a product of a residual magnetization amount and a thickness of the recording layer,
• wherein a ratio Y/X of a sub-peak height Y near a zero magnetic field to a main peak height X in an SFD (Switching Field Distribution) curve is not more than 0.5,
• wherein a coefficient of variation is not more than 30%, and
• wherein the coefficient of variation is represented by the following formula (1):
• coefficient of variation [%]=([Standard deviation of particle diameter]/[Average particle diameter])×100. . . (1).