Nanoscale magnets to increase information storage
Researchers are investigating newly discovered molecules that have the potential to realise increased information storage capacity in smaller storage devices. Single molecule magnets (SMMs) and single-chain magnets (SCMs) have been found to retain their magnetisation in the absence of a magnetic field below a blocking temperature. Lanthanide ions in these systems present a high magnetic moment and anisotropy which, thanks to slow relaxation, help retain the magnetisation. However, there is still much to be learned about these novel 4f-based structures; highly dense metals with high melting points, lanthanide or 'rare earth' elements have a similar electronic structure in terms of the inner 4f electrons. TċċThe 'Theoretical basis for the design of Lanthanide-based molecular nanomagnets' (4FNanomag) project sought to cover this gap in knowledge so as to support the design of 4f-based nanomagnets for use in technological applications. The EU-funded project aimed to establish a methodology that would elucidate the magnetic behaviour and slow relaxation of the magnetisation of lanthanide-based SMMs. This approach combined experimental measurements, first-principle electronic calculations and theoretical magnetic models. ċċExperimental data and first-principle electronic computations revealed that a specific quantum chemistry method can correctly predict the direction of the magnetic moments of lanthanide ions as well as the structure of their energy levels. Other experiments succeeded in realising a first step towards understanding the mechanism of slow relaxation of the magnetisation in lanthanide-based SMMs. Project partners also found that certain systems are well indicated for applications in quantum computation. The study of various lanthanide-containing systems enabled the team members to enhance understanding of related energy levels, barriers and the mechanism of slow relaxation.
