title: Magnetic ordering and anisotropy in heavy atom radicals.
abstract: Recent developments in stable radical chemistry have afforded "heavy atom" radicals, neutral open-shell (S = 1/2) molecular species containing heavy p-block elements (S, Se), which display solid-state magnetic properties once considered exclusive to conventional metal-based magnets. These highly spin-delocalized radicals do not associate in the solid state and yet display extensive networks of close intermolecular interactions. Spin density on the heavy atoms allows for increased isotropic and spin-orbit mediated anisotropic exchange effects. Structural variations induced by chemical modification and physical pressure, coupled with ab-initio methods to estimate exchange energies, have facilitated the development of predictive structure/property relationships. These results, coupled with detailed theoretical analyses and magnetic resonance spectroscopic measurements, have provided insight into the magnetic structure of ferromagnetic and spin-canted antiferromagnetic ordered materials as well as an understanding of the importance of spin-orbit coupling contributions to magnetic hysteresis and anisotropy. Isotropic and anisotropic ferromagnetic exchange can also be enhanced indirectly by the incorporation of heavy atoms into nonspin-bearing sites, where they can contribute to multi-orbital spin-orbit coupling.
authors.affiliation: †Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Winter
authors.affiliation: ‡National High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, Florida 32310, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Hill
authors.affiliation: †Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Oakley