Molecular magnets

Abstract

Magnetic materials in which the fundamental building block is molecular have attracted a great deal of interest because they capitalize on the flexibility inherent in carbon chemistry. Some compounds incorporating chemically stable free radicals are purely organic and show long-range magnetic order at very low temperatures, but the most useful molecular magnets incorporate transition metal or lanthanide ions, with the molecular groups providing a bridge to mediate exchange interactions between the ions. Some of these materials exhibit a spin crossover effect between low-spin and high-spin states. Other molecular magnets form model low-dimensional magnetic compounds that can be used to test models of quantum spin systems. Molecular nanomagnets are complex molecules containing a number of metal ions whose individual moments conspire to create a giant magnetic moment associated with the entire molecule. These systems can be used to exhibit quantum tunnelling of magnetization and are also candidate systems for quantum computing applications.

Acknowledgements

It is pleasure to thank various colleagues for stimulating discussions about molecular magnets and for fruitful collaboration: Arzhang Ardavan, Eugenio Coronado, Bill Hayes, Amit Keren, Mohammedally Kurmoo, Tom Lancaster, Christopher Landee, Jamie Manson, Eric McInnes, Francis Pratt, Juergen Schnack, John Schlueter, Tadashi Sugano and Richard Winpenny.