Qualifications & Memberships
My main research interests are the electronic structure and transition intensities of visible and UV transitions within 4fN configurations and between the 4fN and 4fN-1 5d configurations of lanthanide (rare-earth) ions in various compounds. These materials have complex spectra with sharp lines and so an extremely detailed comparison between theory and experiment is possible.In addition to their intrinsic scientific interest, lanthanide compounds have technological applications, being widely used in fluorescent lamp and TV phosphors, laser materials, and fibre-optical amplifiers. Recent research has focused on the dynamical properties of excited states of lanthanide ions, probed by laser and x-ray techniques. We have also developed techniques to relate ab-initio calculations to spectroscopiec energy-level models. Our current focus is on the understanding of materials that have potential for quantum-information applications, and on nanoparticles for biomedical imaging.
- Horvath SP., Wells JPR., van der Meer AFG. and Reid MF. (2017) An infrared pump-probe measurement of the Sm3+ 6H7/2 lifetime in LiYF4. Optical Materials 66: 8-11. http://dx.doi.org/10.1016/j.optmat.2017.01.026.
- Hughes-Currie RB., Ivanovskikh KV., Wells J-PR., Reid MF., Gordon RA., Seijo L. and Barandiarán Z. (2017) X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF2:Yb but Not in SrF2:Yb.. Journal of Physical Chemistry Letters 8(6): 1175-1178. http://dx.doi.org/10.1021/acs.jpclett.7b00262.
- Mackeen C., Bridges F., Kozina M., Mehta A., Reid MF., Wells JPR. and Barandiarán Z. (2017) Evidence That the Anomalous Emission from CaF2:Yb2+ Is Not Described by the Impurity Trapped Exciton Model. Journal of Physical Chemistry Letters 8(14): 3313-3316. http://dx.doi.org/10.1021/acs.jpclett.7b01103.
- MacKeen C., Bridges F., Seijo L., Barandiarán Z., Kozina M., Mehta A., Reid MF. and Wells JPR. (2017) The Complexity of the CaF2:Yb System: A Huge, Reversible, X-ray-Induced Valence Reduction. Journal of Physical Chemistry C 121(51): 28435-28442. http://dx.doi.org/10.1021/acs.jpcc.7b09161.
- Senanayake PS., Wells JPR., Reid MF., Hughes-Currie RB., Berden G., Reeves RJ. and Meijerink A. (2017) Temporal dynamics of the frequency non-degenerate transient photoluminescence enhancement observed following excitation of inter-configurational f→d transitions in CaF2:Yb2+. Journal of Luminescence 192: 608-615. http://dx.doi.org/10.1016/j.jlumin.2017.07.053.