Ferromagnetic ordering in new layered copper octacyanometallates

Abstract A new family of cyano-bridged bimetallic magnets is presented. These are copper (Cu II ) octacyanometallates based on the [W V (CN) 8 ] 3− or [Mo V (CN) 8 ] 3− precursors, which show soft ferromagnetic properties with T c =28–38.5 K. Ferromagnetism can be attributed to the interaction through the CN-bridges of the unpaired Cu II (3d x 2 − y 2 ) and W V (5d z 2 ; 5d x 2 − y 2 ) (or Mo V ) electrons. The layered structure brings about the quasi-2D character of the magnetic coupling. In-plane positive correlations above T c can be inferred from the heat capacity and magnetic susceptibility data.