MAT Seminar: Investigations of optical, atomic and chemical propertie...

MAT Seminar: Investigations of optical, atomic and chemical propertie...


Speaker: Burcu Öğüt, Şişecam Science Technology and Research Center

Title: Investigations of optical, atomic and chemical properties of thin films and glass materials at the nanoscale

Date/Time: October 16, 2019  /  13.40-14.30

Place: FENS 2019

Abstract: Nanotechnology has emerged as a major field of research enabling a large number of technological breakthroughs which were previously thought unattainable. Potential applications span an enormous range from energy harvesting and storage to the manipulation of optical and electronic properties.

Probing material phenomena at this spatial scale also entails a novel set of characterization tools. Towards this aim, innovative methods which can probe collective excitations such as surface plasmons have gained momentum within the course of last decade. These methods complement the reach of existing tools for structural and chemical characterization. In this seminar, illustrative examples where state-of-the art nanoscale characterization techniques provide valuable insight into different functional materials are presented.

In the first part, chemical and morphological inhomogeneities in complex oxide electrocatalytic thin films used for solid oxide fuel cell applications are studied. Herein, we investigate ~100 nm thick La0.6Sr0.4CoO3-δ (LSC) and La0.6Sr0.4 FeO3-δ (LSF) films deposited onto (100) oriented STO and YSZ substrates with pulsed laser deposition via aberration corrected transmission electron microscopy, and electron energy loss spectroscopy in scanning transmission electron microscopy mode (1).

The second part is devoted to the imaging of coherent collective oscillations of quasi-free electrons on a metal surface under electromagnetic illumination, more specifically the surface plasmon resonances. Plasmonic coupling behaviour of nanoholes with rectangular and circular shapes drilled onto ~100 nm thick Ag films are captured with energy-filtering transmission electron microscopy methods in the Sub-Electron-volt Sub-Angstrom Microscope (Zeiss SESAM). The electromagnetic nature of these excitation modes are elucidated with simulation techniques based on finite element (FEM) and three-dimensional finite difference time-domain methods (3D-FDTD) (2,3).

Finally, we provide an overlook into the recent advances in glass technology which heavily rely on nanoscale phenomena and the pertinent characterization tools. Relevant examples include the use of multilayer thin film stacks, nanoporous materials and coatings which contain dispersed nanoparticles for attaining various filters operating at optical and near IR frequencies; and using glass surface functionalization to enable thinner and lighter glass components for glassware, automotive and construction markets (4).

(1) B. Ogut et al, Microscopy & Microanalysis 2015, 2-6 August 2015, Portland, Oregon, USA, P11.P2 Advances in Transmission Electron Microscopy and Spectroscopy of Energy Related Materials

(2) B.Ögüt et al, ACS Nano, 5, (2011), 6701-6706.

(3) B.Ögüt et al, Nano Lett., 12, (2012), 5239-5244.

(4) C. Kayaalp et al, Glass & Optical Materials Division Annual Meeting, 2018, Texas, USA.

BIO: Dr. Burcu Öğüt is a Lead Researcher at Surface Technologies Department of Şişecam Science Technology and Design Center. Burcu has a Bachelor of Science degree in Metallurgical and Materials Engineering from Middle East Technical University (2006). She received her PhD Degree in Materials Science and Engineering from Christian-Albrechts-University of Kiel, Germany and Max Planck Institute for Intelligent Systems, Stuttgart Germany (2013). During her PhD studies, she focused on investigations of surface plasmon resonances by energy-filtering Transmission Electron Microscopy (EFTEM) methods.

Before joining Şişecam, Burcu worked as a postdoctoral scholar at Stanford University, Department of Materials Science and Engineering, continuing her studies with the investigations of solid oxide fuel cell materials with high resolution transmission electron microscopy and electron energy loss spectroscopy methods (2014-2016). Burcu’s main research interests involve characterization of thin films and nanoparticles using Transmission Electron Microscopy and Scanning Electron Microscopy Methods, as well as and glass surface functionalization techniques in order to enable thinner and lighter glass components for glassware, automotive and construction markets.

Contact: Emre Erdem