Metallic magnetic powder and manufacturing method of the same, magnetic painting, magnetic powder for magnetic therapy, and magnetic recording medium

Abstract

A metallic magnetic powder where a primary particle of each metallic magnetic particle is a powder without forming an aggregate, and a method of making the same that includes manufacturing a metallic magnetic powder constituted of metallic magnetic particles, containing a metallic magnetic phase, with Fe, or Fe and Co as main components, rare earth elements or yttrium and one or more non-magnetic components removing the non-magnetic component from the metallic magnetic with a reducing agent, while making a complexing agent exist for forming a complex with the non-magnetic component in water; oxidizing the metallic magnetic particle with the non-magnetic component removed; substituting water adhered to the oxidized metallic magnetic particle with an organic solvent; and coating the surface of the metallic magnetic particle with an organic matter different from the organic solvent, while maintaining a wet condition of the metallic magnetic particle with the organic solvent adhered thereto.

What is claimed is: 
     
         1 . A metallic magnetic powder constituted of metallic magnetic particles, comprising Fe, or Fe and Co as main components, having an average major axis diameter of 10 to 50 nm confirmed by a transmission electronic microscopic image, having a calculated particle volume of 2500 nm 3  or smaller, and having a value of a peak diameter calculated by a wet-type particle size measurement (DLS method) in a range of 10 to 200 nm. 
     
     
         2 . The metallic magnetic powder according to  claim 1 , wherein a value of a relative ratio (peak diameter/average major axis diameter) of the average major axis diameter obtained by the transmission electronic microscopic image, and a peak diameter calculated by the DLS method is 5 or smaller. 
     
     
         3 . A metallic magnetic powder constituted of metallic magnetic particles, having a metal phase comprising Fe, or Fe and Co as main components, having an oxide layer on the surface of the metal phase, with the surface of the oxide layer coated with an organic matter having a molecular weight of 100 or larger. 
     
     
         4 . The metallic magnetic powder according to  claim 3 , wherein the organic matter is a high molecule having polydispersity of 1.05 to 2.0. 
     
     
         5 . The metallic magnetic powder according to  claim 3 , wherein the organic matter has a structure containing a sulfonic acid group and/or a phosphonic acid group. 
     
     
         6 . A magnetic painting adopting the metallic magnetic powder according to  claim 1 . 
     
     
         7 . A magnetic powder for magnetic therapy adopting the metallic magnetic powder according to  claim 1 . 
     
     
         8 . A magnetic recording medium adopting the metallic magnetic powder according to  claim 1 .