Soft magnetic powder, method for producing same, and dust core using soft magnetic powder

A soft magnetic powder comprising:

• a soft magnetic powder layer of an unoxidized soft magnetic material;
• a second oxide layer as an oxide with iron or boron residing around the soft magnetic powder layer;
• and
• a first oxide layer of an iron oxide residing around the second oxide layer, wherein:
• the first oxide layer and the second oxide layer reside in a region of 20 nm or more and 500 nm or less from a surface of the soft magnetic powder, and are absent in a region of more than 500 nm and 1,600 nm or less from the surface,
• the first oxide layer has a spiked pulverization mark on a powder surface layer, and
• an angle formed by the spiked pulverization mark with respect to the powder surface is 30 to 60 degrees.

A soft magnetic powder comprising:

• a soft magnetic powder layer of an unoxidized soft magnetic material;
• an oxide layer of an iron oxide residing around the soft magnetic powder layer;
• and
• a silicon containing layer covering a surface layer of the oxide layer without a break,
• the soft magnetic powder having a silicon concentration that continuously increases from a central portion of the soft magnetic powder layer toward a surface layer of the soft magnetic powder layer, and the oxide layer being configured from a first oxide layer residing on the surface-layer side, and a second oxide layer of an oxide with iron or boron residing on the soft-magnetic-powder-layer side.

A soft magnetic powder comprising:

• a soft magnetic powder layer of an unoxidized soft magnetic material;
• an oxide layer of an iron oxide residing around the soft magnetic powder layer;
• and
• a silicon containing layer covering a surface layer of the oxide layer without a break, wherein:
• the soft magnetic powder has a silicon concentration that continuously increases from a central portion of the soft magnetic powder layer toward a surface layer of the soft magnetic powder layer, and
• the silicon containing layer has a silicon concentration that is 0.5 atomic % to 3 atomic % higher than the silicon concentration of the soft magnetic powder layer.

A soft magnetic powder comprising:

• a soft magnetic powder layer of an unoxidized soft magnetic material;
• a second oxide layer which is an oxide containing boron and resides around the soft magnetic powder layer;
• and
• a first oxide layer of an iron oxide residing around the second oxide layer, wherein:
• the first oxide layer and the second oxide layer reside in a region of 20 nm or more and 500 nm or less from a surface of the soft magnetic powder, and are absent in a region of more than 500 nm and 1,600 nm or less from the surface.

A soft magnetic powder comprising:

• a soft magnetic powder layer of an unoxidized soft magnetic material;
• a second oxide layer as an oxide with iron or boron residing around the soft magnetic powder layer;
• and
• a first oxide layer of an iron oxide residing around the second oxide layer, wherein:
• the first oxide layer and the second oxide layer reside in a region of 20 nm or more and 500 nm or less from a surface of the soft magnetic powder, and are absent in a region of more than 500 nm and 1,600 nm or less from the surface, and
• a total amount of surface oxygen of the first oxide layer and the second oxide layer is 6.81% by weight.