Iron-based oxide magnetic powder, and green compact and radio wave absorber using the same

An objective of this invention is to provide an iron-based oxide magnetic powder having excellent thermal stability and small variation in radio wave absorption even in a high temperature environment, which is composed of [epsilon]-iron oxide particles with a part of Fe sites being replaced by other metal elements, a radio wave absorber using the iron-based oxide magnetic powder, a green compact using the iron-based oxide magnetic powder, and a method for manufacturing the same. According to the present invention, an iron-based oxide magnetic powder having excellent thermal stability and small variation in radio wave absorption even in a high temperature environment, which is composed of [epsilon]-iron oxide particles with a part of Fe sites being replaced by other metal elements, is obtained by coexisting of phosphorus-containing ions when a precipitate of iron hydroxide containing substituting metal elements, which is produced by neutralizing an acidic aqueous solution containing trivalent iron ions and met