Davison Lecture - Jeffrey R. Long, University of California, Berkeley

About this event

Davison Lecture Part 2 Ultrahard Lanthanide-Based Single-Molecule Magnets Jeffrey R. Long Departments of Chemistry, Chemical and Biomolecular Engineering, and Materials Science and Engineering University of California, Berkeley Materials Sciences Division, Lawrence Berkeley National Laboratory Abstract: Scientists have long employed lanthanide elements in the design of materials with extraordinary magnetic properties, including the strongest magnets known, SmCo5 and Nd2Fe14B. The properties of these materials are largely a product of fine-tuning the interaction between the lanthanide ion and the crystal lattice. Over the past two decades, synthetic chemists have learned to utilize lanthanide elements for the construction of single-molecule magnets—molecules that retain polarization upon removal from an applied magnetic field. Importantly, the desirable magnetic characteristics of the lanthanides are contingent upon the interaction between the single-ion electron density and the crystal field environment in which it is placed. Taking advantage of this interaction, new approaches for synthesizing lanthanide-based single-molecules magnets with high operating temperatures will be presented. Focus will be on recent work involving: (i) high-temperature magnetic blocking and magneto-structural correlations in lanthanide(III) metallocenium and lanthanide(II) metallocene complexes, (ii) the synthesis and characterization of radical-bridged dilanthanide complexes exhibiting strong magnetic exchange and high blocking temperatures, (iii) the realization of double-exchange and very large coercivities in mixed-valence dilanthanide complexes with metal-metal bonding, and (iv) efforts to couple many lanthanide centers through nanoscale graphene fragments. Refreshments will be served outside of 34-101 at 3:45PM.