Positronium Probing of Pores in Zirconia Nanopowders
I. Prochazkaa, J. Cizek a, F. Lukac a, O. Melikhova a, P. Hruska a, W. Anwand b, M.O. Liedke b, T.E. Konstantinova c and I.A. Danilenko c
aCharles University, Faculty of Mathematics and Physics, Department of Low Temperature Physics, V Holesovickach 2, CZ-180 00 Praha 8, Czech Republic
bHelmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstr. 400, 01328 Dresden, Germany
cNational Academy of Sciences of Ukraine, Donetsk Institute for Physics and Engineering named after O.O. Galkin, Nauki av. 46, 03028 Kiev, Ukraine
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In the present paper, conventional positron lifetime measurements on selected zirconia-based nanopowders are reported. The nanopowders were doped with various metal cations (Y3+, Eu3+, Gd3+, Lu3+ and Mg2+). Lifetime experiments were conducted in air and supplemented with mass density measurements. In a range of lifetimes, from a few ns to ≈70 ns, up to two individual lifetime components could be identified. Such observations confirmed positronium (Ps) formation with subsequent ortho-Ps pick-off annihilation as well as the occurrence of pores of different size. Pore sizes were estimated using a shape-free model of the correlation between pore size and ortho-Ps lifetime. The origins of pores are discussed on the basis of the ortho-Ps data in combination with the results of mass density measurements.

DOI: 10.12693/APhysPolA.132.1564
PACS numbers: 81.07.Wx, 61.46.Hk, 78.70.Bj