  We calculated the influence of surface tension on the barriers of oxygen
ionic conductivity in nanograin ceramics. Activation energy of oxygen ions
diffusion via oxygen vacancies which were considered as the dilatational
centers was calculated. This energy was shown to decrease with nanoparticle
sizes decreasing. The distribution function of activation energy was derived on
the basis of distribution of nanoparticle sizes. We obtained an analytical
expressions of ionic conductivity dependence on the temperature and nanograin
sizes. These formulas fitted pretty good the observed earlier behaviour of
oxygen conductivity in nanograin ceramics of ZrO2:16% Y observed earlier.
Therefore the consideration we carried out had shown that the surface tension
in nanoparticles is physical mechanism responsible for the essential
enhancement of the oxygen ionic conductivity observed in nanograin samples, the
main contribution to the conductivity being related to the region in vicinity
of the particle surface.
