Synthesis and characterization of molecular materials showing slow magnetic relaxation and magnetic memory effect

• Applicant: Professorin Roberta Sessoli, Ph.D.
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2002 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5369289

The project concerns the study of the relatively novel phenomenon of the presence of magnetic hysteresis in the absence of long range magnetic order. This field of research has been opened by the applicant almost ten years ago with the discovery that a molecular cluster comprising twelve paramagnetic metal ions strongly coupled to give a large spin in the ground state show very slow magnetic relaxation at low temperature (Sessoli et al. Nature 1993, 365, 141). The applicant has also been involved in a related area of research, i. e. the existence of slow relaxation of the magnetization in strictly one-dimensional material in the absence of interactions between the chains. Such a phenomenon has been predicted almost forty years ago (Glauber J. Math. Phys. 1963, 4, 294-307) but only recently observed for the first time by the applicant (Caneschi et al. Angew. Chem. Intern. Ed. 2001, 40, 1760-1763). The project will mainly focus on the synthesis and characterization of other 1-d magnetic material exhibiting slow magnetic relaxation, in order to better understand this new phenomenon. The role played by the inter-chain interactions, as well as the presence of defects (finite chain effects) will be investigated through the synthesis and characterization of doped chains. A second aspect of this research will be the investigation of hysteretic behavior in zero-d materials (clusters) characterized by strongly anisotropic interactions.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1137: Molecular Magnetism
• International Connection: Italy