The magnetic rare-earth ions (for example, triply ionized holmium) introduced at small concentrations into single crystal Lithium Yttrium Fluoride, form a class of nanoscale materials called single-ion magnets. These systems are relatively new and exhibit a fascinating variety of magnetic phenomena associated with the coupled electro-nuclear states of the holmium ion. Not only are these systems scientifically interesting, but they possess important technological relevance for the development of q-bits for quantum computers and for the development of dense magnetic recording media. This project uses Nuclear Magnetic Resonance (NMR), muon spin resonance and AC thermal measurements to study these nanomagnets. The results from these experiments will be used to understand the spin dynamics and decoherence in this system via interactions with the surrounding atoms and to characterize the onset of magnetic correlations as a function of increasing dipolar coupling strength, which is changed by varying holmium ion concentration. Studies on a related interesting hybrid single-ion molecular magnet terbium di-pthalocyanine, will also be carried out.
This project is a collaborative effort involving research groups at the University of Pavia, Italy, the Louis Néel Laboratory in Grenoble, France, and Boston College. In addition, the muon user facilities at ISIS - Rutherford Appleton Laboratory (UK), and the Paul Scherrer Institute (Switzerland) will be used to carry out parts of the proposed research. Additional scientific support for the project through sample fabrication and theoretical analysis involves colleagues at the Vavilov Optical Institute and Kazan State University in Russia, respectively. Thus the proposed work will provide US graduate and undergraduate students with exceptional educational opportunities through extended research visits to some of the above laboratories and by participation in formal training workshops for NMR and muon spectroscopy at European facilities. Furthermore, the US junior researchers will gain valuable experience in the field of molecular magnetism, and become familiar with techniques of muon spin spectroscopy, areas in which the US is currently under-represented.
This award is co-supported by the Division of Materials Research and the Office of International Science and Engineering.
