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Details of Grant 

EPSRC Reference: EP/K008722/1
Title: Single-molecule magnetism in lanthanide organometallics
Principal Investigator: Layfield, Professor RA
Other Investigators:
Collison, Dr D Winpenny, Professor RE McInnes, Professor EJL
Researcher Co-Investigators:
Project Partners:
Department: Chemistry
Organisation: University of Manchester, The
Scheme: Standard Research
Starts: 18 February 2013 Ends: 17 February 2016 Value (£): 346,522
EPSRC Research Topic Classifications:
Chemical Structure Co-ordination Chemistry
EPSRC Industrial Sector Classifications:
No relevance to Underpinning Sectors
Related Grants:
Panel History:
Panel DatePanel NameOutcome
26 Sep 2012 EPSRC Physical Sciences Chemistry - September 2012 Announced
Summary on Grant Application Form
Molecules that have a magnetic memory are called single-molecule magnets (SMMs). In terms of their size and composition, SMMs have dimensions of a few nanometres and they consist of one or more metal atoms bonded to a group of non-metal atoms called a ligand. The interactions between neighbouring molecules are very weak, meaning that the magnetic properties of an SMM genuinely arise from within individual molecules.

In stark contrast to SMMs, traditional 'bar' magnets used in everyday appliances are purely inorganic materials such as metal oxides or simply magnetic elements. A particularly important example of their application is in computer hard disk drives. In terms of their size and composition, rather than consisting of molecules traditional magnets feature much larger magnetic domains.

Because one of the main differences between SMMs and traditional magnets relates to size, it is possible that SMMs represent the ultimate size limit for magnetic information storage. The properties of SMMs may one day allow them to be developed for use in quantum computers. A problem with SMMs is, however, that their magnetic memories function at temperatures of about -250oC, which can only be reached by cooling with liquid helium and is therefore impractical. Furthermore, the mechanisms by which SMMs relax their magnetization (i.e. the magnetic information is lost or 'wiped') are not clear, but it is likely that gaining an understanding of these processes will lead to enhanced performance at higher temperatures.

We propose a new family of SMMs based on the lanthanide elements (Ln-SMMs). The lanthanides offer considerable potential for developing SMMs because these elements have particularly appealing magnetic properties. Ultimately, our Ln-SMMs will have magnetic memory effects observable above -196oC, which will be a major advance because this temperature can be reached by cooling with liquid nitrogen, a cryogen that is much cheaper than liquid helium, and easier to use.

We will achieve our aims by using a molecular design tool available to us as synthetic chemists: we can make significant changes to the ways in which our ligands interact with our choice of lanthanide. This is important because the non-metal atoms used to interact with the lanthanides, and the symmetry with which the ligands are arranged around the lanthanides, allow us to influence the magnetism.

A unique aspect of our approach to the design of Ln-SMMs is that our synthetic method gives access to an extremely broad range of chemical environments. Existing, conventional Ln-SMMs are almost entirely limited to ligands in which oxygen or nitrogen interacts with the lanthanide, however we can influence the magnetism using carbon, oxygen, sulphur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony or the halogens.

By understanding the ways in which the different chemical environments influence the molecular magnetism we will be able to identify the optimum conditions for producing Ln-SMMs that function at unprecedentedly high temperatures.
Key Findings
Potential use in non-academic contexts
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Organisation Website: http://www.man.ac.uk