Abstract
PALS experiments reveal a minimum in ortho-positronium (o-Ps) lifetimes and a maximum in the corresponding intensities that emerge when mixed-cation (Li/Na) borate glasses are heated from ambient temperatures up to 473 K. These free volume 'anomalies' appear to be a true manifestation of the mixed alkali effect (MAE). They are consistent with a mechanism of ion transport involving cooperation between hops of unlike cations, resulting in increased disturbance of the glass network. The result lends support to the dynamic structure model.
Original language | English |
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Pages (from-to) | 1620-1623 |
Number of pages | 4 |
Journal | Physical Chemistry Chemical Physics |
Volume | 7 |
Issue number | 8 |
Early online date | 15 Mar 2005 |
DOIs | |
Publication status | Published - Mar 2005 |