On the origin of differential phase contrast at a locally charged and globally charge-compensated domain boundary in a polar-ordered material
On the origin of differential phase contrast at a locally charged and globally charge-compensated domain boundary in a polar-ordered material
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DOI：
10.1016/j.ultramic.2015.03.016
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发表时间：
2015-07-01
期刊：
影响因子：
2.2
通讯作者：
Dunin-Borkowski, Rafal E.
中科院分区：
文献类型：
--
作者：
MacLaren, Ian;Wang, LiQiu;Dunin-Borkowski, Rafal E.
利用扫描电子显微镜中的DPC成像技术，研究了掺杂铋铁氧体中的带电反相区边界。可以看到一个清晰的差分信号，它与边界上电场的预期方向相匹配。然而，扫描衍射的进一步研究表明，一次衍射盘没有可测量的偏转，因此材料中没有明显的自由电场。相反，DPC信号产生于边界附近的初级衍射盘内的强度分布的调制。模拟结果表明，这种调制纯粹是由晶界结构的局部变化引起的，而不是由电场引起的。这项研究强调了在使用DPC成像和其他相位对比度技术解释从铁电材料记录的信号时所需的谨慎。(C)2015年提交人。爱思唯尔出版公司(Elsevier B.V.)
Differential phase contrast (DPC) imaging in the scanning transmission electron microscope is applied to the study of a charged antiphase domain boundary in doped bismuth ferrite. A clear differential signal is seen, which matches the expected direction of the electric field at the boundary. However, further study by scanned diffraction reveals that there is no measurable deflection of the primary diffraction disc and hence no significant free E-field in the material. Instead, the DPC signal arises from a modulation of the intensity profile within the primary diffraction disc in the vicinity of the boundary. Simulations are used to show that this modulation arises purely from the local change in crystallographic structure at the boundary and not from an electric field. This study highlights the care that is required when interpreting signals recorded from ferroelectric materials using both DPC imaging and other phase contrast techniques. (C) 2015 The Authors. Published by Elsevier B.V.