Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 15: Mechanical Properties III
MM 15.3: Vortrag
Montag, 26. März 2012, 16:15–16:30, H 0106
Theoretical study of dislocations in perovskite oxides — •Pierre Hirel1,2, Matous Mrovec1,2, and Christian Elsaesser1,2 — 1IAM-ZBS, Karlsruhe Institute for Technology, Engelbert-Arnold-Straße 4,76131 Karlsruhe (Germany) — 2Fraunhofer-Institut für Werkstoffmechanik IWM, Wöhlerstr. 11, 79108 Freiburg (Germany)
Perovskite oxides such as barium-strontium titanate, lead zirconate-titanate, or potassium-sodium niobate are a technologically important and scientifically exciting class of materials. Many perovskites are ferroelectric and possess high dielectric constants, which make them attractive for modern microelectronic applications. A successful implementation however requires not only information about the intrinsic functional properties but also a thorough understanding of crystal defects that influence the functionality as well as the mechanical and structural stability of such components.
In the present work we investigate the properties of dislocations in perovskite materials by means of atomistic simulations, using both the highly accurate first-principles calculations and computationally efficient classical interatomic potentials. We analyze the structures of dislocation cores in comparison to high-resolution transmission electron microscopy observations. The calculated Peierls energies and stresses for these dislocations under different applied loads give insight into their mobilities and are related to their macroscopic mechanical behavior.
(1) P. Hirel et al., Acta Mater. 60 (2012) 329