Segregation-induced grain boundary electrical potential in ionic oxide materials: A first principles model

A first principles continuum analytical model for cationic segregation to the grain boundaries in complex ceramic oxides is presented. The model permits one to determine the electric charge density and the segregation-induced electric potential profiles through the grain and can be extrapolated to the range of nanostructured grain sizes. The theoretical predictions are compared with existing data for yttria-stabilized tetragonal zirconia polycrystals. The implications for physical properties (mainly high temperature plasticity and hardening behaviour) are then discussed. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
The authors wish to acknowledge the financial support awarded by the Spanish Research authorities through the Projects MAT2009-14351-C02-01 and MAT2009-14351-C02-02. D.G.G. would like to acknowledge the encouraging scientific atmosphere found in the Tokyo Research Institute during his stays at that institution, hosted by Prof. F. Wakai and sponsored by the Japan Society for the Promotion of Science.