Polarization in Ferroelectrics Measured by CBED in STEM Mode - Practical Electron Microscopy and Database - - An Online Book - |
||||||||
Microanalysis | EM Book https://www.globalsino.com/EM/ | ||||||||
================================================================================= | ||||||||
Tsuda et al. [1] were able to observe the two-dimensional (2D) distribution of the small atomic displacements (~10 pm) cased by the ferroelectric polarization in the rhombohedral phase of the tetragonal BaTiO3 nanostructures using the CBED method in STEM mode. They demonstrated that this is a highly sensitive technique for detecting such small atom displacements or symmetry breaking. In the analysis of ferroelectric polarization with STEM-CBED technique, one needs first to make sure: With simultaneous HAADF imaging and CBED patterning, Tsuda et al. [1] employed the intensity difference (or called symmetry breaking) between the 020 and 0-20 reflections, (I020-I0-20)/I020, to map the directions of polarizations in tetragonal BaTiO3 nanostructures because the two reflections give the highest sensitivity theoretically and experimentally.
[1] Kenji Tsuda, Akira Yasuhara, and Michiyoshi Tanaka, Two-dimensional mapping of polarizations of rhombohedral nanostructures in the tetragonal phase of BaTiO3 by the combined use of the scanning transmission electron microscopy and convergent-beam electron diffraction methods, Applied Physics Letters, 103, 082908 (2013).
|
||||||||
================================================================================= | ||||||||
|
||||||||