RED MAGNETIC POWDER AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain red magnetic powder, assuming red color itself and useful as a raw material for inks or color toners by mixing respective compounds of magnesium, zinc and iron in a specific proportion and calcining the resultant mixture. CONSTITUTION:The above-mentioned red magnetic powder consists of a ferromagnetic metallic oxide expressed by the following composition formula. That is formula (MgO)x(ZnO)y(Fe2O3)z (x, y and z are as follows; 0.2<=x<=1.0; 0.9<=z<=1.0 and x+y=1). The afore-mentioned red magnetic powder is obtained by the following method. That is an inorganic salt of magnesium or magnesium oxide or both are blended with an inorganic salt of zinc and/or zinc oxide and an inorganic salt of iron and/or iron oxide so that the atomic ratios (magnesium : zinc : iron) of the above-mentioned metallic compounds may satisfy the relation between x, y and z in the afore-mentioned composition formula. The obtained mixture is subsequently calcined at 1100-1300 deg.C in a reducing atmosphere. After the calcining, the resultant calcined substance is then preferably annealed at 400-800 deg.C.