Seiko Epson Corporation

Mitsutaka Inui

Mayu Watanabe

A soft magnetic powder contains a particle having a composition represented by FeCuNb(SiB), and 0.3≤a≤2.0, 2.0≤b≤4.0, and 72.5≤x≤75.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10)x. The particle includes a crystal grain having a grain size of 1.0 nm to 30.0 nm, a Cu segregation portion, and a crystal grain boundary. A content proportion of the crystal grain is 30% or more. When the Cu segregation portion positioned in a surface layer portion and having a grain size of 1.0 nm to 5.0 nm is referred to as a first Cu segregation portion, and the Cu segregation portion positioned in an inner portion and having a grain size of 3.0 nm to 10.0 nm is referred to as a second Cu segregation portion, a number proportion of the first Cu segregation portion is 80% or more, and a number proportion of the second Cu segregation portion is 80% or more.

Soft magnetic powder, dust core, magnetic element, and electronic device

A soft magnetic powder contains a particle having a composition represented by FeCuNb(SiB), and 0.3≤a≤2.0, 2.0≤b≤4.0, and 75.5≤x≤79.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10)x. The particle includes a crystal grain having a grain size of 1 nm to 30 nm, a Cu segregation portion, and a crystal grain boundary. A content proportion of the crystal grain is 30% or more. When the Cu segregation portion positioned in a surface layer portion and having a grain size of 2 nm to 10 nm is referred to as a first Cu segregation portion, and the Cu segregation portion positioned in an inner portion and having a grain size of 2 nm to 7 nm is referred to as a second Cu segregation portion, a number proportion of the first Cu segregation portion is 80% or more, a number proportion of the second Cu segregation portion is 80% or more, and the number of the second Cu segregation portion is twice or more the number of the first Cu segregation portion.

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Fujimi, Japan

Mitsutaka Inui