Interdisziplinäres Zentrum für Materialwissenschaften
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Interdisziplinäres Zentrum für Materialwissenschaften
Nanotechnikum Weinberg
Heinrich-Damerow-Str. 4,
D-06120 Halle, Germany
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S. Thraenert, E. M. Hassan, D. Enke, D. Fuerst, R. Krause-Rehberg
Verifying the RTE model: ortho-positronium lifetime measurement on controlled pore glasses.
phys. stat. sol. (c) 4, 10 (2007), 3819-3822

In porous media, the vacuum lifetime of ortho-positronium (o-Ps) of ? = 142 ns can be reduced markedly by pick-off annihilation (interaction with electrons of the host material). So the o-Ps lifetime is determined by the pore size which can be extracted by utilising approved models like the Tao-Eldrup model for pore sizes smaller than 1 nm and the Tokyo model or RTE model for larger pore sizes. The RTE model contains an explicit temperature dependence of the o-Ps lifetime. Experiments on controlled pore glasses (CPG) with different pore sizes (2-70 nm) at different temperatures (50-500 K) were performed to verify the RTE model. A general agreement for T = 300 K could be found. The temperature dependence of the lifetime, especially for low temperatures, could not be approved sufficiently.

Keywords: model; positron annihilation; lifetime; porous; temperature dependence
© Wiley-VCH 2007

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