| 摘要 |
A ferromagnetic chromium dioxide stabilized by coating the particles thereof with a stabilizing substance is disclosed, wherein the stabilizing substance consists essentially of an equimolecular mixture of Fe2O3 and MnO or of a mixture of ferrite MeFe2O4 with oxides Fe2O3 and MeO, wherein Me represents Cu, Co, Zn or Mg and wherein the molar ratio Fe2O3/MeO is equal to 1, the quantity of the ferrite in the mixture being such as results from calcining, at temperature between 250 DEG and 350 DEG C., equimolecular quantities of Fe2O3 and MeO. A process for obtaining the stabilized CrO2 is also disclosed wherein the CrO2 is dispersed in water and on it are co-precipitated Fe(OH)3 and Mn(OH)2 or Me(OH)2 in stoichiometric quantities with respect to each other; after which the CrO2, in admixture with the hydroxides, is separated from the water, dried at a temperature not exceeding 100 DEG C. and then calcined at temperatures between 250 DEG and 350 DEG C.
|
