Magnetic Properties Of Rare Earth-iron Oxalate-bridged Complexes

Cyano-bridged polynuclear complexes are a kind of Ferromagnetic compounds that have high critical temperature now, and rare earth-iron cyano-bridged complexes have been reported in the literature, but the crystal structure of rare earth-iron Oxalate-bridged complexes and the size of the magnetic interaction between rare earth ion and iron ion have not been reported,yet there are the literature on the preparation of LaFe(C₂O₄)₃·9H₂O,but no detailed information on its structure.And the literature on the preparation found the strong magnetic interaction between Nd³⁺ and Fe³⁺ .Therefore the essay uses transition metal ions as the spin carrier, oxalate as bridging ligand to design and synthesis the rare earth - oxalate-bridged complex, for example, Ce Fe (C₂O₄)₃·9H₂O, Pr Fe(C₂O₄)₃·9H₂O. Infrared analysis, thermogravimetric analysis, elemental analysis and ICP-AES are used to characterize the samples, and measure the variable temperature magnetic susceptibility of the complexes finding that measuring the temperature from room temperature to low temperature,the complex shows the change from the paramagnetic phase to antiferromagnetic phase and the phase transition point is near 5K.thus the magnetic properties showed typical paramagnetic interaction.The essay studies the law of the magnetic properties presented by the lanthanide due to the contraction of its lanthanide,which provides a possible basis for shows the change for the further study of synthesis and magnetic properties of oxalate-bridged rare earth - transition metal ( Fe³⁺ ) complexes .