High Resistivity Compressed Magnetic Core

Abstract

A powder compressed magnetic core, which is produced by compressing iron powder or alloy powder of which the main component is iron. A fluoride compound layer of a fluoride of a rare earth element or a fluoride of an alkaline earth metal is formed on the surface of the powder, and an under layer is formed between the fluoride layer and the iron powder or the alloy powder.

1 . A powder compressed magnetic core, which is produced by compressing iron powder or alloy powder of which the main component is iron, wherein a fluoride compound layer of a fluoride of a rare earth element or a fluoride of an alkaline earth metal is formed on the surface of the powder, and wherein an under layer is formed between the fluoride layer and the iron powder or the alloy powder. 
     
     
         2 . The powder compressed magnetic core according to  claim 1 , wherein the under layer contains an alkaline earth metal and an oxide of the rare earth element or alkaline earth metal. 
     
     
         3 . The powder compressed magnetic core according to  claim 1 , wherein the under layer contains at least one member selected from the group consisting of Mg, Ca, Ba and Sr. 
     
     
         4 . The powder compressed magnetic core according to  claim 1 , wherein a total thickness of the under layer and the fluoride layer is 100 nm or less, and a thickness of the under layer is 50 nm or less. 
     
     
         5 . The powder compressed magnetic core according to  claim 1 , wherein the fluoride is magnesium fluoride. 
     
     
         6 . A powder compressed magnetic core, which is produced by compressing iron powder or alloy powder of which the main component is iron, wherein a fluoride compound layer of a fluoride of a rare earth element or a fluoride of an alkaline earth metal is formed on the surface of the powder, wherein an under layer is formed between the fluoride layer and the iron powder or the alloy powder, wherein the under layer contains an alkaline earth metal and an oxide of an alkaline earth metal, wherein the under layer has a layer containing oxygen, next to the iron powder, and wherein the under layer has a layer containing oxygen and fluoride, next to the fluoride compound layer. 
     
     
         7 . The powder compressed magnetic core according to  claim 6 , wherein the alkaline earth metal is calcium.