论文标题
通过多尺度电子显微镜研究，在多效GA0.6 Fe1.4O3薄膜中揭示非常规的铁电开关
Unveiling Unconventional Ferroelectric Switching in Multiferroic Ga0.6 Fe1.4O3 Thin Films Through Multiscale Electron Microscopy Investigations
论文作者
论文摘要
了解铁电材料中发挥的极化开关机制对于它们在电子设备中的剥削至关重要。对于大多数常规位移性的铁电材料中，基于中心对称结构的常规参考结构机制对于某些新诊断的铁电材料（例如GA2-XFEXO3（0.8 <x <x <1.4））来说，它的能量太高了。已经提出了一些替代理论命题，需要实验确认。对GA0.6FE1.4O3多表情化合物的薄膜进行了双尺度电子显微镜研究。大规模的疗程辅助电子衍射断层扫描研究首先允许确定化合物在薄膜中采用的结构，甚至允许在该结构内的原子位置进行完善。通过存在额外的电子密度，建议对两个原子位置提出阳离子迁移率。然后，一项局部原位高分辨率扫描透射电子显微镜研究允许通过直接在连续获得的图像上发现阳离子位移来确认这些迁移率。整个研究证实了通过该化合物中局部结构域壁运动的非常规切换机制。
Understanding the polarization switching mechanisms at play in ferroelectric materials is crucial for their exploitation in electronic devices. The conventional centrosymmetric reference structure-based mechanism which accounts for ferroelectricity in most of the usual displacive ferroelectric materials is too energy-demanding for some newly diagnosed ferroelectric materials such as the Ga2-xFexO3 (0.8 < x < 1.4) compounds. Some alternative theoretical propositions have been made and need experimental confirmation. A dual-scale electron microscopy study is performed on thin films of the Ga0.6Fe1.4O3 multiferroic compound. A wide scale precession-assisted electron diffraction tomography study first allows the determination of the structure the compound adopts in thin films, and even permits the refinement of the atomic positions within this structure. Cationic mobility is suggested for two of the atomic positions through the existence of extra electronic density. A local in situ high resolution scanning transmission electron microscopy study then allows confirming these mobilities by directly spotting the cationic displacements on successively acquired images. The whole study confirms an unconventional switching mechanism via local domain wall motion in this compound.
