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

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy2 L2 (μ-Cl)2 (thf)2 ] has been made by using a diamine-bis(phenolate) ligand, H2 L. Magnetic studies show an energy barrier for magnetisation reversal (Ueff ) around 1000 K. An exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 3 K. Ab initio calculations exclude the possibility of a pure dipolar origin of this effect leading to the conclusion that super-exchange through the chloride bridging ligands is important.