Exchange-Biasing in a Dinuclear Dysprosium(III) Single-Molecule Magnet with a Large Energy Barrier for Magnetization Reversal

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy₂L₂(µ-Cl)₂(THF)₂] has been made using a diamine-bis(phenolate) ligand, H₂L. Magnetic studies show an energy barrier for magnetization reversal (U_eff) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. Ab initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange via the chloride bridging ligands is important.