Ferromagnetic cpd. with improved magnetic properties - consists of a solid soln. of chromium di:oxide and rhodium di:oxide

摘要

Ferromagnetic cpd. based on CrO2 and RhO2 of formula Cr1-xRhxO2 (where x is 0-0.5 (is approx. 0.1)), is mfd. by oxidn. at 350-500 degrees C and >400 bar, of hydrated Cr2O3 or its precursor, in the presence of an appropriate amt. of Rh (III) cpd. which forming RhO2 under the conditions of the reaction; and an oxygenerated cpd. free of metallic cations other than Cr, which does not lead to the preferential or parasitic formation of chromates, bichromates or any other cpd. with degree of oxidn. >4. A partial pressure of oxygen at least equal to those corresponding to the equilibrium Cr2O3+1/2O2. >=2 CrO2 and Rh2O3+1/2O2 >=2 RhO2. is provided, opt. together with water of dilution and/or >=1 dopant acting as buffer in the reaction medium and a classical modifier. The cpd. exhibits improved magnetic proportion c.f. unmodified CrO2.