Magnetic Bistability in Lanthanide-Based Molecular Systems: The Role of Anisotropy and Exchange Interactions

Lanthanide-based molecular magnets started to be systematically investigated in the 2000s, showing new types of magnetic properties and new opportunities. In particular, the discovery that slow relaxation of the magnetization at liquid nitrogen temperature can occur in mononuclear complexes of these ions prompted an intense wave of investigation on these systems. In this chapter, we summarize the historical developments and the more recent advances in this field. We stress the need of combined high level ab initio calculations and single-crystal multitechnique characterization to obtain a reliable picture of the electronic structure of these systems and the way this is reflected in their static and dynamic magnetic properties. Indeed, magnetic bistability in lanthanide-based molecular materials results from a subtle interplay between magnetic anisotropy and magnetic exchange and the optimization of both is far from trivial. We conclude this chapter by raising some prospects into the future development of lanthanide-based molecular magnets in the emerging fields of quantum information processing and molecular spintronics.