Method for producing soft magnetic metal powder coated with mg-containing oxide film and method for producing composite soft magnetic material using said powder

A method for producing a soft magnetic metal powder coated with a Mg-containing oxide film used for producing a composite soft magnetic material having resistivity of 65 μΩm or more, comprising the steps of:

• adding and mixing a Mg powder with a soft magnetic metal powder to obtain a mixed powder;
• and heating said mixed powder at a temperature of 150 to 1,100° C. in an inert gas or vacuum atmosphere under a pressure of 1×10−12 to 1×10−1 MPa,
• followed by heating said heating mixed powder in an oxidizing atmosphere at a temperature of 50 to 400° C. to effect oxidation treatment, thereby obtaining a soft magnetic metal powder coated with a Mg-containing oxide film,
• wherein said soft magnetic powder is an iron powder, an insulated powder, Fe—Al iron-based soft magnetic alloy powder, Fe—Ni iron-based soft magnetic alloy powder, Fe—Cr iron-based soft magnetic alloy powder, Fe—Si iron-based soft magnetic alloy powder, Fe—Si—Al iron-based soft magnetic alloy powder, Fe—Co iron-based soft magnetic alloy powder, Fe—Co—V iron-based soft magnetic alloy powder, or Fe—P iron-based soft magnetic alloy powder, and
• wherein said soft magnetic metal powder is used for producing a composite soft magnetic material having resistivity of 65 μΩm or more.