Cambridge 7th to 9th September
Presenting Author:
Gavin Mountjoy
<g.mountjoy@kent.ac.uk>
article posted 16 Mar 2015
GavinMountjoy
Dr Gavin Mountjoy is Reader in Condensed Matter Physics at the University of Kent.
He first studied Physics at Victoria University of Wellington where he obtained a BSc.
A Commonwealth Scholarship enabled him to undertake a PhD in the Microstructural
Physics Group at the Cavendish Laboratory, University of Cambridge. This was followed
by work as a Research Associate in the Center for Solid State Science at Arizona State
University, U.S.A. In 2001 Gavin was appointed as a Lecturer in the School of Physical
Sciences at University of Kent. In 2005-2006 undertook a Marie Curie Intra-European
Fellowship in the Functional Materials Group, University of Cagliari, Italy. Gavin returned
to School of Physical Sciences at University of Kent in 2007 as a Senior Lecturer.
Getting more light from luminescence of lanthanide doped glasses
Gavin Mountjoy
School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
Lanthanide, or rare earth, doped glasses are key technological materials because they place
the luminescent properties of rare earth ions within a transparent refractive medium [e.g. 1].
Increasing the rare earth dopant concentration, N, initially causes an increase in the
luminescence (∝N). At higher dopant concentrations the proximity (r) of rare earth
ions becomes closer (∝N-3) [e.g. 2], and luminescence is quenched due to the higher
likelihood of non-radiative transitions (∝r-6). In the literature the quantities of critical
concentration (Nc) or critical radius (rc) are used to describe the threshold at which
luminescence quenching becomes dominant. The present work examines the fundamental
pair distribution function for random dopants, including the most likely nearest neighbour
distances, r1. This provides an approach to quantitatively predict the effect of dopant
concentration on luminescence quenching. The predictions for r<rc give the fraction
of dopants for which luminescence is effectively quenched, and for r>rc give the
reduction in luminescence for the remaining dopants. These predictions are compared
with values of critical radius reported in the literature.
References:
[1] T. Qin, G. Mountjoy, N.D. Afify, M.F. Reid, Y.-Y. Yeung, A. Speghini and M. Bettinelli (2011) Phys. Rev. B 84 104206 - "Link between optical spectra, crystal field parameters, and local environments of Eu3+ ions in Eu2O3 doped sodium disilicate glass".
[2] N. Afify and G. Mountjoy (2009) Phys. Rev. B 79 024202 - "Molecular dynamics modeling of Eu3+ ion clustering in SiO2 glass".