Ootsuki Shirou, Ikeno Hidekazu, Umeda Yuji, Yonezawa Yu, Moriwake Hiroki, Kuwabara Akihide, Kido Osamu, Ueda Satoko, Tanaka Isao, Fujikawa Yoshinori, Mizoguchi Teruyasu
Advanced Technology Development Center, TDK Corporation, 2-15-7 Higashi-Ohwada, Ichikawa-shi, Chiba 272-8558, Japan Institute of Industrial Science, The University of Tokyo 4-6-1, Komaba, Meguro, Tokyo 153-8505, Japan
Nanoscience and Nanotechnology Research Center, Research Organization for 21st Century, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan.
Microscopy (Oxf). 2014 Jun;63(3):249-54. doi: 10.1093/jmicro/dfu011. Epub 2014 Apr 15.
Identification of local strains is crucial because the local strains largely influence the ferroelectric property of BaTiO₃. The effects of local strains induced by external pressures on the Ti-L₂,₃ electron energy-loss near-edge structure (ELNES) of BaTiO₃ were theoretically investigated using first-principles multiplet calculations. We revealed that the effects appear in the position of the spectral threshold, namely the spectrum shifts to lower and higher energy sides by the tensile and compressive pressures, respectively. We concluded that conventional ELNES observations can identify only large strains induced by -10 GPa, and 0.1 eV energy resolution is required to identify ±2% of strains.
识别局部应变至关重要，因为局部应变在很大程度上影响BaTiO₃的铁电性能。利用第一性原理多重态计算从理论上研究了外部压力引起的局部应变对BaTiO₃的Ti-L₂,₃电子能量损失近边结构（ELNES）的影响。我们发现，这些影响出现在光谱阈值位置，即分别在拉伸和压缩压力下光谱向较低和较高能量侧移动。我们得出结论，传统的ELNES观测只能识别由-10 GPa引起的大应变，而识别±2%的应变需要0.1 eV的能量分辨率。
