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Sintering and grain growth in SrTiO3: impact of defects on kinetics

Lemke, Fabian; Rheinheimer, Wolfgang; Hoffmann, Michael J.

Abstract: The microstructural evolution of undoped and iron doped SrTiO3 is analyzed during sintering at 1280°C in air and reducing atmosphere. The focus is on densification and grain growth during different holding times investigated by dilatometric studies and microstructural analysis. The sintering equations developed by Coble are used to characterize sintering. The influence of point defects on diffusion, densification and grain growth is evaluated using basic defect chemistry equations. A space charge concept at the grain boundaries is added to bulk defect chemistry concepts to understand sintering of perovskites, since the major part of mass transport during sintering occurs in this region. The extension of the defect chemistry concept allows to explain the change in diffusion mechanism during sintering (grain boundary diffusion or bulk diffusion) as well as grain growth stagnation observed in iron doped SrTiO3. The results are used to separate the complex interplay of densification and grain growth. While grain growth decreases with increasing defect concentration, no clear trend is observed for the densification kinetics, since both grain growth and diffusion are relevant. The results show that grain growth during sintering provides comparable results to grain growth experiments in dense SrTiO3 and, thus, pore drag seems not to be important. The calculated diffusion coefficients are in good agreement with literature data and show a strong dependency on the concentration of strontium vacancies.


Zugehörige Institution(en) am KIT Institut für Keramik im Maschinenbau (IKM)
Institut für Angewandte Materialien - Keramik im Maschinenbau (IAM-KM)
Institut für Angewandte Materialien - Keramische Werkstoffe und Technologien (IAM-KWT)
Publikationstyp Zeitschriftenaufsatz
Jahr 2016
Sprache Englisch
Identifikator DOI: 10.2109/jcersj2.15265
ISSN: 0912-9200
KITopen ID: 1000053230
Erschienen in Journal of the Ceramic Society of Japan
Band 124
Heft 4
Seiten 346-353
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