Phase-Field Modeling for Oxygen Vacancy Fluctuations in Complex Oxide Heterostructures

Dr. Vitalii Starchenko

Abstract: Understanding the dynamic behavior of defects in the complex oxides is key to controlling ionic and electronic properties in these multifunctional materials.  Measurements of point defect dynamics in epitaxial thin films of using X-ray Photon Correlation Spectroscopy show that the defects (oxygen vacancies) exhibit cooperative behavior dependent on the epitaxial strain state.  We observe that elastic strain within the film, due to coherency at the film-substrate interface, controls dynamic behavior and self-organization of oxygen vacancies.

In this talk, a semi-quantitative description of the defect behavior using phase-field modeling will be presented. The simulations demonstrate that the elastic strain between substrate and film control fluctuations and spontaneous phase transition.

Speaker’s Bio: Vitalii Starchenko is a research scientist in the Geochemistry and Interfacial Sciences Group, Chemical Sciences Division, Oak Ridge National Laboratory.  Since completing his Ph.D. in physics of colloidal systems in 2009 (Institute of Biocolloid Chemistry, Kyiv, Ukraine), he occupied a postdoctoral position at Max Planck Institute for Polymer Research in Mainz (Germany) 2011-2013, and a postdoctoral position at the Department of Chemical Engineering, University of Florida (Gainesville, Florida) 2014-2016.  His research is focused on phase transformations in heterogeneous systems, reaction kinetics and transport at fluid-solid interfaces, coupling of molecular scale processes and chemistry in porous geomaterials to macroscopic phenomena, and use of machine learning tools to qualitatively improve chemical identification in X-ray tomography imaging techniques

Last Updated: February 21, 2023 - 3:43 pm