A composite magnetic material includes a powder and a resin. The powder has a main component containing Fe or Fe and Co. An average minor axis length in primary particles of the powder is 100 nm or less. A point satisfying (X, Y)=(σ/A.sub.v (%), (A.sub.v-σ)) on an XY coordinate plane is present within a region (including a boundary) surrounded by three points α(24.5, 6.7), β(72.0, 1.2), and γ(24.5, 1.2), in which an average of aspect ratios in the primary particles of the powder is set to A.sub.v, and a standard deviation of the aspect ratios in the primary particles of the powder is set to σ.

Disclosed herein is a composite magnetic powder that includes an iron-containing magnetic powder and an insulating layer comprising a silicon oxide formed on a surface of the iron-containing magnetic powder. The insulating layer contains pores, and an area ratio of the pores in a cross section of the insulating layer is 5% or less.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material, the second resin material having a softening point higher than the first resin material.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material, the second resin material having a softening point higher than the first resin material.

A soft magnetic powder includes soft magnetic metal particles. The soft magnetic metal particles include metal particles and oxide parts covering the metal particles. Each of the metal particles at least include Fe. Each of the oxide parts at least include Fe and Mn. Concentration distributions of Mn of the soft magnetic particles have maximum concentrations of Mn in the oxide parts.

A magnetic core has a structure in which Fe-based soft magnetic alloy particles are connected via a grain boundary. The Fe-based soft magnetic alloy particles contain Al, Cr and Si. An oxide layer containing at least Fe, Al, Cr and Si is formed at the grain boundary that connects the neighboring Fe-based soft magnetic alloy particles. The oxide layer contains an amount of Al larger than that in Fe-based soft magnetic alloy particles, and includes a first region in which the ratio of Al is higher than the ratio of each of Fe, Cr and Si to the sum of Fe, Cr, Al and Si, and a second region in which the ratio of Fe is higher than the ratio of each of Al, Cr and Si to the sum of Fe, Cr, Al and Si. The first region is on the Fe-based soft magnetic alloy particle side.

A composite magnetic body includes soft magnetic metal particles and non-magnetic ceramic particles each having a particle size (D50) smaller than that of the soft magnetic metal particles.

A soft magnetic metal powder including a soft magnetic metal particle. The soft magnetic metal particle includes a metal particle and an oxide part covering the metal particle. An interface between the metal particle and the oxide part has roughness. A maximum height Rz of roughness at the interface between the metal particle and the oxide part is within a range of 1.0 nm or more and 50.0 nm or less.

The present invention provides a magnetic core having insulating properties, and a method for manufacturing the magnetic core. Provided is a magnetic core manufactured by compression molding and subsequent thermal curing of an iron-based soft magnetic powder having a resin coating formed on particle surfaces thereof. The iron-based soft magnetic powder is one in which the particle surfaces have been coated with an inorganic insulator; the resin coating is an uncured resin coating formed by dry blending the powder with a thermosetting resin at a temperature equal to or greater than the softening point of the thermosetting resin and lower than the thermal curing initiation temperature of the resin; the compression molding is carried out by using a mold to produce a compression molded body; and the thermal curing is carried out at a temperature equal to or greater than the thermal curing initiation temperature of the thermosetting resin.

The present invention provides a magnetic core having insulating properties, and a method for manufacturing the magnetic core. Provided is a magnetic core manufactured by compression molding and subsequent thermal curing of an iron-based soft magnetic powder having a resin coating formed on particle surfaces thereof. The iron-based soft magnetic powder is one in which the particle surfaces have been coated with an inorganic insulator; the resin coating is an uncured resin coating formed by dry blending the powder with a thermosetting resin at a temperature equal to or greater than the softening point of the thermosetting resin and lower than the thermal curing initiation temperature of the resin; the compression molding is carried out by using a mold to produce a compression molded body; and the thermal curing is carried out at a temperature equal to or greater than the thermal curing initiation temperature of the thermosetting resin.