caa a22 4500 445362774 CHVBK 20180317142920.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s10832-009-9577-8 doi (NATIONALLICENCE)springer-10.1007/s10832-009-9577-8 Modeling of transport properties of interfacially controlled electroceramics: Application to n-conducting barium titanate [Elektronische Daten] [W. Preis, W. Sitte] Grain boundary regions in n-conducting barium titanate (BaTiO3) are re-oxidized during the cooling process after sintering the ceramics in air. The kinetics of this re-oxidation process is determined by rapid transport of oxygen along the grain boundaries and slow (rate-determining) diffusion of cation vacancies from the grain boundaries into the grains until the diffusion process is frozen-in. Based on numerical calculations of frozen-in diffusion profiles of cation vacancies at grain boundary regions for various cooling rates, a modified Schottky-barrier model is introduced in order to calculate the grain boundary resistivity as a function of temperature from the Curie-point up to 900°C. A change of the activation energy at approximately 500°C is predicted owing to an enrichment of holes in the space charge layers at elevated temperatures. The modeling results are compared with experimental data for BaTiO3-based positive temperature coefficient resistors (PTCRs). Springer Science+Business Media, LLC, 2009 Donor-doped BaTiO3 nationallicence Re-oxidation kinetics nationallicence Diffusion profiles nationallicence Grain boundary resistivity nationallicence Schottky-barrier model nationallicence Preis W. Chair of Physical Chemistry, University of Leoben, Franz-Josef-Strasse 18, A-8700, Leoben, Austria aut Sitte W. Chair of Physical Chemistry, University of Leoben, Franz-Josef-Strasse 18, A-8700, Leoben, Austria aut Journal of Electroceramics Springer US; http://www.springer-ny.com 27/2(2011-10-01), 83-88 1385-3449 27:2<83 2011 27 10832 https://doi.org/10.1007/s10832-009-9577-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10832-009-9577-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Preis W. Chair of Physical Chemistry, University of Leoben, Franz-Josef-Strasse 18, A-8700, Leoben, Austria aut NATIONALLICENCE 700 1- Sitte W. Chair of Physical Chemistry, University of Leoben, Franz-Josef-Strasse 18, A-8700, Leoben, Austria aut NATIONALLICENCE 773 0- Journal of Electroceramics Springer US; http://www.springer-ny.com 27/2(2011-10-01), 83-88 1385-3449 27:2<83 2011 27 10832 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer