Stator core, stator, rotary electric machine, and method of manufacturing stator core

A stator core configured to be used in an axial-gap rotary electric machine, the stator core comprising:

• a plurality of teeth with columnar shape,
• wherein the stator core has
• a peripheral surface of each of the plurality of teeth,
• a first end surface of each of the plurality of teeth,
• at least one second end surface that is a surface opposite to the first end surfaces,
• wherein each of the plurality of teeth is formed of a dust core,
• wherein the dust core includes a plurality of coated particles,
• wherein each of the plurality of coated particles includes
• a metallic particle made of a soft magnetic material, and
• an electrically insulating coating covering the metallic particle,
• wherein each of the first end surfaces has
• first regions formed of cross sections of the metallic particles, and
• second regions formed of the electrically insulating coatings between the first regions,
• wherein each of the peripheral surfaces is made of an oxide containing a constituent element of the soft magnetic material, and
• wherein an average thickness of the oxide in each of the peripheral surfaces is 10 μm or less.