Ferroelectric Nanostructures

Department of Materials Science and Engineering* Pohang Accelerator Laboratory, Pohang University of Science and Technology, Korea ** Max Planck Institute of Microstructure Physics, Germany***
Songhak Yoon* Hee Han* Yongjun Park*,** Min Gyu Kim** Namsoo Shin** Ran Ji*** Dietrich Hesse*** Marin Alexe*** Kornelius Nielsch*** Ulrich Goessele*** â—‹Sunggi Baik*

A number of synchrotron radiation facilities and their users have been growing rapidly world wide and have feasted new important discoveries and excitement in various scientific and technological areas including materials science, biological science, electronics, environmental engineering, etc. Drastic improvements in time, spatial, energy, and spectroscopic resolutions have been realized in comparison to the conventional light sources and provided strong motivations to revisit many unresolved scientific issues. Ferroelectrics have been one of such issues that have been explored extensively using this new light source in recent years. In this presentation, some of recent attempts and discoveries in studying various issues related to ferroelectric nanostructures including ultra thin films and nano-islands are summarized to demonstrate the unique features and opportunities of synchrotron radiation.
In addition, as an example, our recent study on domain structures in the epitaxial PZT thin films and nano-islands will be described in detail. Evolution of unique domain structures were characterized as a function of film compositions, substrate selection, film thickness, and 2D planar size employed in film fabrication. The c-domain abundance and crystalline quality of the films are studied and quantified by two-dimensional reciprocal space mapping technique in the PLS 3C2 and 10C1 X-ray Scattering Beamlines equipped with in-situ high temperature stages and 2C1 X-ray microscopy. Domain switching dynamics are studied by AFM. Attempts have been also made theoretically to establish the correlation with various electrical and thermomechanical factors involved in nano structure processing.