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FM: Fachverband Funktionsmaterialien

FM 16: Topical Session: Dislocations in Functional Materials II (joint session MM/FM)

FM 16.2: Vortrag

Mittwoch, 11. März 2026, 16:15–16:30, SCH/A251

Probing the Known Unknown of the Dislocation Dynamics in Oxides and Semiconductors — •Liming Xiong — NC State University, Raleigh, NC, USA

Dislocation dynamics in oxides and semiconductors are widely aware, but its exact nature and impact on the properties and functionality of these materials are not fully understood yet. One reason is that the well-established knowledge for dislocation dynamics in metals often can't fully explain or even fail when used for oxides and semiconductors. To fill this knowledge gap, here we will present a concurrent atomistic-continuum computational tool for probing the dislocation dynamics in oxides and semiconductors. This tool has a unique feature to accommodate the motion/multiplication of μm-long dislocations together with the atomic-scale core structure evolution along the dislocation within all within one single model. Taking dislocation-seeded SrTiO3 and ZnS as sample materials, we will: (i) map the core structure/stress along a dislocation line to its local charge states and motion mechanism; (ii) measure the dislocation mobility and its dependence on stress, temperature, dopant concentration, charge states, electrical field, light illumination, and dislocation line lengths ranging from nanometers to micrometers; (iii) predict how local internal stress builds up when a mesoscale dislocation slip interacts with an atomically structured grain boundaries, and how such a high local stress may initiate a crack in turn. A consolidation of such simulation data into constitutive rules needed by higher-scale models for interpreting experimental observations will be also discussed.

Keywords: Dislocation Mobility, Multiplication, and Pileup; Oxides and Semiconductors; Atomistic and Multiscale Modeling; Core Stress and Structure; Kinks and Vacancies