Atomic Structure and Chemistry of extended defects in SrTiO3 based materials
Dr. Hongchu Du
Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons
Research Centre Jülich, Germany
Time: 10:00-11:00, July 16 (Thursday)
Place: MSE building Room 210
Abstract:
Strontium titanate (SrTiO3) and their solid solutions are important members in the class of perovskite structures with a general formula ABO3. These materials are of great technological and fundamental importance not only because of their interesting properties, such as high dielectric permittivity, switchable resistance, ionic conductivity, and ferroelectricity, but also because of the ability to combine and to adjust these properties by chemical substitution with a wide variety of cations. Moreover, combination of materials with similar structure to form superlattices allows additional degrees of freedom in tuning the final properties. It has been shown that lattice defects can be very detrimental to many properties and phenomena of SrTiO3 based materials and devices. Therefore, a profound knowledge on the atomic structure and chemistry of a large variety of defects is a prerequisite for a comprehensive understanding the underlying mechanism of the defect-associated effects. In this talk, I will discuss several examples, where aberration corrected HAADF-STEM, EELS, and EDX imaging techniques are used to reveal the atomic structures and chemistry of defects in SrTiO3 based materials.
Speaker:
Dr. Hongchu Du is a research staff scientist in the Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons at The Research Centre Jülich and works in the area of high-resolution transmission electron microscopy (HRTEM). His research mostly focuses on quantitative HRTEM and spectroscopy, as well as in image processing and image simulation. Before joining ER-C in 2012, he spent three years in Institute of Inorganic Chemistry in University Bonn as a postdoctoral researcher, where he worked in the area of characterization of nanocrystals by HRTEM. He also had a short time stay at Institute of Physical Chemistry in University Mainz. He received his Doctoral degree in Chemistry in 2008 from Dresden University of Technology, Germany, and Master degree in Chemical Technology in 2004 from the Institute of Process Engineering, the Graduate School of Chinese Academy of Sciences. After he got his Bachelor degree in Materials Chemistry in 1999 from Chinese University of Geosciences, Beijing, he had worked for two years as a research assistant at Changchun Institute of Applied Chemistry, CAS.
