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Mechanism of the decrease of barriers for oxygen ionic conductivity in nanocrystalline ceramics
Author(s) -
Glinchuk M. D.,
Bykov P. I.,
Hilczer B.
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200642052
Subject(s) - ionic conductivity , nanocrystalline material , conductivity , activation energy , ionic bonding , ceramic , materials science , oxygen , nanoparticle , diffusion , surface tension , ion , chemical physics , nanotechnology , chemistry , thermodynamics , composite material , physics , electrolyte , electrode , organic chemistry
Abstract We calculate the influence of surface tension on the barriers for oxygen ionic conductivity in nanograin ceramics. Namely, we evaluate the activation energy for diffusion of oxygen ions via its vacancies. In our model, latter vacancies have been considered as dilatational centers. We have shown, that the activation energy decreases with nanoparticle size decreasing. We derive the distribution function of activation energy on the base of distribution of nanoparticle sizes. We obtain analytical expressions for dependence of ionic conductivity on the temperature and nanograin sizes. The obtained expressions describe the observed behaviour of oxygen conductivity in nanograin ceramics of ZrO 2 :16% Y pretty good. Our theoretical studies show that the surface tension in nanoparticles is indeed a physical mechanism responsible for the essential enhancement of the oxygen ionic conductivity observed in nanograin samples, where the main contribution to the conductivity goes from the region near the particle surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)