Project B1: Exploring Magnetic Relaxation in Dinuclear 4f Compounds Using Theory and Experiment

The aim of the project is to explore the details of the electronic structures of Ln₂ dinuclear compounds by combining experiment and theory to discover why and how two 4f ions are often better than one in terms of Single Molecule Magnet (SMM) behavior. For open shell single 4f ions, the promise of utilizing the high anisotropy of just one of these, typically Ising type, ions to provide SMMs is often hard to realize because of available zero-field quantum tunneling of the magnetization (ZFQTM) pathways enabling tunneling through the energy barrier. Quenching ZFQTM requires either imposing very strict local symmetry constraints on the 4f ion(s) or removing the ground state degeneracy through application of a static magnetic field. In earlier research we found that by the removal of ZFQTM in this way relaxation properties can be improved and a deeper understanding of other factors can be generated with follow-up experiments. However, providing the correct local symmetry is a significant synthetic challenge, and although some truly impressive progress has been made in designing and synthesizing such molecules, these suffer from the drawback that they often involve unstable chemical species and require anaerobic conditions in the synthesis and handling of the subsequent materials. The objectives are to synthesize families of dinuclear compounds and to characterize and analyze their magnetic behavior by experiment and theory. 
 

Project leaders: 
Prof. Dr. Annie Powell (KIT) 
Prof. Dr. Karin Fink (KIT)