PURPOSE: To obtain alloy powder of a ferromagnetic metal having an excellent magnetic characteristic and dispersibility by treating needlelike iron oxyhydroxide of a raw material with a tin compd. and subjecting the same to a reduction treatment after calcination.
CONSTITUTION: Needlelike iron oxyhydroxide is suspended in water or in a hydrophilic org. solvent and about 0.05W15wt% tin compd. expressed in terms of Fe2O3 is dissolved in the raw material and both are stirred and mixed. The treated needlelike iron oxyhydroxide is calcined at about 500W900°C and is reduced at about 300W700°C after filtering and washing. The collapsion of particle shape and sintering are prevented and the metallic magnetic powder having an improved magnetic characteristic is obtd. by the above-mentioned method.
| JP2008105346 | MAGNETIC INFORMATION RECORDING MEDIUM |
OGATA YASUNOBU
IIMURA TSUTOMU
