Single molecule magnets (SMMs) are an area of significant research due to their potential applications for data storage, magnetic refrigeration and quantum computing. SMMs are molecules that have the properties of bulk magnets but also show quantum effects such as quantum tunnelling of the magnetisation. One class of molecules that have been found to be SMMs are lanthanide (bis) phthalocyanines, also known as double deckers. These complexes contain a single lanthanide ion which is 'sandwiched' between two phthalocyanine rings. This class of SMMs have been found to have large energy barriers to magnetic relaxation making them suitable for magnetic data storage applications. In this Thesis four new substituted lanthanide double deckers have been successfully synthesised and characterised. The substituents added to the phthalocyanine rings include cyano groups, esters, carboxylic acids and imides. The double deckers magnetic properties were investigated using a superconducting quantum interference device (SQUID) magnetometer and some complexes were found to have their magnetic properties changed by the addition of the substituents, in some cases the magnetic properties are improved. All complexes have been found to show magnetic hysteresis and slow relaxation of the magnetisation in an oscillating field, indicating that the complexes are SMMs. A range of other measurements were carried out to determine their magnetic and electronic properties, including far infrared (FIR) spectroscopy and magnetic circular dichroism (MeD) spectroscopy. The internal structure of the double deckers was probed with extended X-ray absorption fine structure (EXAFS) spectroscopy to investigate the effect that the substituents have on the structure
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602425 |
| Date | January 2013 |
| Creators | Waters, Michael |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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