Thickness dependence of crystal and electronic structures within heteroepitaxially grown BiFeO3 thin films
Thickness dependence of crystal and electronic structures within heteroepitaxially grown BiFeO3 thin films
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DOI：
10.1103/physrevb.93.064115
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发表时间：
2016-02-24
影响因子：
3.7
通讯作者：
Sato, Kazuhisa
中科院分区：
文献类型：
--
作者：
Bae, In-Tae;Naganuma, Hiroshi;Sato, Kazuhisa
利用先进的透射电子显微镜（TEM）技术研究了在SrTiO 3衬底上生长的BiFeO 3薄膜（10 nm和300 nm）的晶体结构和电子结构随BiFeO 3薄膜厚度的变化。电子衍射图案的两个BiFeO 3薄膜获得沿着[011]（SrTiO 3）的横截面清楚地表现出额外的布拉格反射的存在下，从SrTiO 3的缺席。结构因子计算明确地揭示了电子衍射图案对应于菱面体BiFeO 3的[211]网图案。高分辨率TEM图像结合多层模拟也表明，这两个BiFeO3薄膜的晶体结构是菱面体。两种BiFeO3薄膜的电子能量损失谱结果显示出具有块状BiFeO3特征的谱，即，菱面体的晶格失配
Crystal and electronic structures of BiFeO3 thin films (similar to 10 and similar to 300 nm) grown on SrTiO3 substrate have been investigated in terms of BiFeO3 film thickness dependence using the advanced transmission electron microscopy (TEM) technique. Electron diffraction patterns of both BiFeO3 thin films acquired along [011](SrTiO3) cross sections clearly exhibited the existence of extra Bragg's reflections which are absent in that from SrTiO3. Structure factor calculations unambiguously revealed that the electron diffraction pattern corresponds to the [211] net pattern of rhombohedral BiFeO3. High-resolution TEM images combined with multislice simulation also demonstrated that the crystalline structure of both BiFeO3 films is rhombohedral. Electron energy loss spectroscopy results for both BiFeO3 thin films showed spectra with the characteristics of bulk BiFeO3, i.e., rhombohedral. The lattice mismatch of