Soft magnetic powder and method for manufacturing the same, coil component including soft magnetic powder, and method for manufacturing magnetic material including soft magnetic powder

Abstract

A soft magnetic powder including a core containing a soft magnetic metal material and an insulating film covering the surface of the core. The insulating film contains an insulating metal oxide and an iron component, and the iron component is embedded in the insulating film.

What is claimed is: 
     
         1 . A soft magnetic powder comprising:
 a core containing a soft magnetic metal material; and   an insulating film covering the surface of the core,   wherein the insulating film contains an insulating metal oxide and an iron component, and the iron component includes an iron component embedded in the insulating film.   
     
     
         2 . The soft magnetic powder according to  claim 1 , wherein
 the iron component is iron oxide.   
     
     
         3 . The soft magnetic powder according to  claim 1 , wherein
 the insulating film includes particles of the iron component.   
     
     
         4 . The soft magnetic powder according to  claim 3 , wherein
 the average particle diameter of the particles of the iron component is from 5 nm to 20 nm.   
     
     
         5 . The soft magnetic powder according to  claim 1 , wherein
 the insulating metal oxide is a hydrolysis product of a metal alkoxide.   
     
     
         6 . The soft magnetic powder according to  claim 1 , wherein
 the insulating film further contains an organic material.   
     
     
         7 . The soft magnetic powder according to  claim 6 , wherein
 the organic material is at least one selected from the group consisting of a water-soluble polymer and a surfactant.   
     
     
         8 . The soft magnetic powder according to  claim 1 , wherein
 the insulating film contains at least one element selected from the group consisting of C, N, and P.   
     
     
         9 . The soft magnetic powder according to  claim 1 , wherein
 the insulating metal oxide is at least one selected from the group consisting of titanium oxide, silicon oxide, aluminum oxide, and zirconium oxide.   
     
     
         10 . The soft magnetic powder according to  claim 1 , wherein
 the core contains an Fe-based, Ni-based, or Co-based soft magnetic metal material.   
     
     
         11 . The soft magnetic powder according to  claim 1 , wherein
 the iron component is not present on the surface of the insulating film.   
     
     
         12 . The soft magnetic powder according to  claim 1 , wherein
 a film of an oxide containing iron is further included, and   the film of the oxide containing iron is disposed in the vicinity of an interface between the insulating film and the core.   
     
     
         13 . A method for manufacturing a soft magnetic powder comprising:
 obtaining a slurry by mixing a core containing a soft magnetic metal material, an iron salt, a metal alkoxide, and at least one selected from the group consisting of a water-soluble polymer and a surfactant in a solvent; and   obtaining a soft magnetic powder including the core and an insulating film covering the surface of the core by drying the slurry.   
     
     
         14 . The method for manufacturing a soft magnetic powder according to  claim 13 , wherein
 the obtaining of a slurry includes hydrolyzing the metal alkoxide.   
     
     
         15 . The method for manufacturing a soft magnetic powder according to  claim 13 , wherein
 the iron salt is soluble in alcohol.   
     
     
         16 . The method for manufacturing a soft magnetic powder according to  claim 15 , wherein
 the iron salt is at least one selected from the group consisting of iron chloride and iron nitrate and hydrates thereof.   
     
     
         17 . The method for manufacturing a soft magnetic powder according to  claim 13 , wherein
 the water-soluble polymer and the surfactant have a ligand capable of forming a complex with an Fe ion.   
     
     
         18 . The method for manufacturing a soft magnetic powder according to  claim 17 , wherein
 the water-soluble polymer is at least one selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, hydroxypropyl cellulose, poly(2-methyl-2-oxazoline), polyethyleneimine, poly acrylic acid, and carboxymethyl cellulose.   
     
     
         19 . A coil component comprising:
 a magnetic core containing the soft magnetic powder according to  claim 1  and a binder; and   a coil conductor.   
     
     
         20 . A method for manufacturing a magnetic material comprising:
 obtaining a formed article by forming the soft magnetic powder according to  claim 1 ; and   obtaining a magnetic material by heat-treating the formed article.