Chemical Physics Letters, Vol.622, 20-22, 2015
The size of smallest subnanometric voids estimated by positron annihilation method. Correction to the Tao-Eldrup model
The Tao-Eldrup model, commonly applied in estimation of free volume sizes in solids, uses the concept of infinitely deep potential well, which can lead to inaccuracies when the ortho-positronium (o-Ps) lifetime is very short (less than 1.5 ns). A simple correction allowing to estimate properly the free volume radii at the o-Ps lifetime down to 0.8 ns is proposed. (c) 2015 Elsevier B.V. All rights reserved.