Phase transitions in new BEDT-TTF κ-phase salts with hexacyanometalate anions [M(CN)63− M=Co(III) and Fe(III)]
Résumé
The preparation, crystal structure determination and physical properties of the compounds formulated as κ-(BEDT-TTF)4((C2H5)4N)M(CN)6.3H2O (M= CoIII and FeIII) are presented. Organic ET layers with packing of orthogonalized dimers containing charge carriers and inorganic octahedral hexacyanometalate anions with diamagnetic or paramagnetic transition metals coexist in the title compounds. Two phase transitions occuring respectively at 150 K and in the 230–260 K range have been evidenced by magnetic (SQUID and ESR), DSC measurements. However, preliminary X-Ray studies revealed a structural change around 240 K only.