Magnetic Studies in Rare Earth-iron Oxalate-bridged Complexes MFe(C2O4)3·9H2O (M=Ce, Pr)

The rare earth-iron oxalate-bridged complexes CeFe(C2O4)3·9H2O and PrFe(C2O4)3·9H2O have been synthesized. In the sample CeFe(C2O4)3·9H2O, the magnetic susceptibilities of the compound can be fit to the Curie-Weiss law and Weiss paramagnetic Curie temperature of θ=-1.4K.the hyperfine field parameters show that the dependent of the hyperfine field and the spontaneous magnetization and that of the spontaneous magnetization and temperature in the latticed FeII and FeIII.There are a clear bifurcation phenomenon of the field-cooled (MFC) and Zero-field-cooled (MZFC) magnetization curves at the Néel temperature (4 K).In the sample PrFe(C2O4)3·9H2O,the Weiss paramagnetic Curie temperature θ=-2.7 K,There are a bifurcation of the ZFC and FC plots at the Néel temperature (6 K).The negative Weiss constant indicates an intramolecular antiferromagnetic coupling interaction between the adjacent Fe(II) and Fe(III) ions through the oxalate bridge.The oxalate group has been shown to be an excellent bridging ligand in supporting the magnetic exchange interaction.