CR-1-XIRXO2 (0-LESS-THAN-X-LESS-THAN-0.3), A FERROMAGNETIC MATERIAL WITH HIGH COERCIVITY

Iridium (IV), due to its high value of spin-orbit coupling constant ca n strongly modify magnetic properties of the ferromagnetic lattice CrO 2. Our experimental data have underlined that coercive fields higher t han 1500-2000 Oe can be reached with small amounts of iridium (x appro ximate to 0.01). A Mossbauer investigation of iridium doped CrO2 revea led that Ir(IV) is mainly stabilized in such a lattice. On the contrar y, after very high oxygen pressure treatment, using belt-type equipmen t an XPS study suggests the presence of Ir(V) close to the surface. A self-consistent band structure calculation precised the antiferromagne tic couplings between iridium and chromium in such a lattice.