Interactions magnétiques dans des groupements binucléaires du Ruthénium +V

The cationic ordering in the $\text{Ba}\text{M}{}_{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}\text{Ru}{}_{\mathrm{<mtext>2</mtext><mtext>3</mtext>}}\text{O}{}_3\text{(M =}\text{Mg, Ca, Cd, Sr}\text{)}$ oxides which crystallize with the 6H structure gives rise to Ru⁵⁺Ru⁵⁺ pairs in (Ru₂O₉) clusters. The magnetic properties have been analyzed on the basis of the Heisenberg-Dirac-Van Vleck model: The d electrons are localized on each Ru⁵⁺ ion and interact strongly through antiferromagnetic exchange. The susceptibility curves agree with the H.D.V.V. model. The values of the exchange integrals have been determined by fitting the experimental values.