Numéro |
J. Phys. IV France
Volume 128, September 2005
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Page(s) | 111 - 114 | |
DOI | https://doi.org/10.1051/jp4:2005128017 |
J. Phys. IV France 128 (2005) 111-114
DOI: 10.1051/jp4:2005128017
Positron annihilation lifetime studies of SrTiO3 crystal and ceramic materials
D.J. Keeble1, S. McGuire1, S. Singh1, B. Su2, T.W. Button2 and J. Petzelt31 Faculty of Engineering and Physical Sciences, University of Dundee, Dundee DD1 4HN, UK
2 IRC in Materials Processing, University of Birmingham, Birmingham B15 2TT, UK
3 Institute of Physics, Academy of Sciences of the Czech Republic, Praha 8, Czech Republic
Abstract
Positron annihilation lifetime spectroscopy (PALS)
measurements on high density ceramic SrTiO3 are reported and compared
to measurements on single crystal substrates. PALS has specific sensitivity
to vacancy-related defects as these are traps for positrons; the lifetime of
vacancy trapped positrons is increased with respect to those that annihilate
from the perfect lattice. Positrons are found to be saturation trapped at
vacancy defects in the ceramic samples, with over 90% annihilating with a
lifetime of 175 ps, and the remainder annihilating with a lifetime in
the 270-310 ps range consistent with A-site or larger open volume sites.
The dominant component at 175 ps may represent a single vacancy trap,
or it may be the average of one or more unresolved lifetime states.
© EDP Sciences 2005