Ferromagnetic metal particles - produced by mixing starting material with another metal oxide and heating the mixture

摘要

Ferromagnetic metal particles are produced from a starting material consisting of oxides, hydroxides or complex hydroxides of ferromagnetic metals from a wet reduction, which is mixed with fine particles of a metal or oxide of Cu, Ag, Mn, Pt or Sn which have a higher oxidation-reduction potential than the metal of the ferromagnetic metal fraction. The mixt. is heat treated at an elevated temp. in a reducing atmos. using for example N2-, CO- or H2 gas. The addn. of another metal or oxide prevents aggregation of the particles during the heat treatment, and accelerates the reduction reaction. Used for the prodn. of magnetic tapes of high density.