PRODUCTION OF GARNET FINE PARTICLE POWDER

PURPOSE:To obtain garnet fine particle powder having excellent corrosion resistance, magnetic optical effect and light transmittance by mixing the compounds of respective elements in a ratio for constituting a specific rare earth-iron garnet, thermally melting the mixture, rapidly cooling the melted mixture, heating the prepared amorphous substance and subsequently treating the substance with acid. CONSTITUTION:The compounds of respective elements selected in a ratio for constituting a rare earth-iron garnet represented by a general formula: RaBibFecMdOe [R is one or more rare earth elements selected from Y and lanthanoid elements; M is one or more elements of Al, Ga, Cr, Mn, Sc, In, Ru, Rh, etc.; a+b+c+d=7.5-8.0; a+b=2.0-3.5; c+d=4.5-6.0; a=0.5-3.5; b=0-2.5; c=3.0-6.0; d=0-2.0; e is the number of oxygen atoms satisfied with the atomic valences of other elements] are mixed with a glass-forming substance, and the mixture is thermally melted and subsequently rapidly cooled to prepared an amorphous substance. The amorphous substance is thermally treated to deposit rare earth-iron garnet fine particles in the amorphous substance, which is treated with an acid to remove the glass-forming substance, thereby providing garnet fine particle powder having an average particle size of 30-1000Angstrom .