Two-dimensional electron gas at the Ti-diffused BiFeO3/SrTiO3 interface
Two-dimensional electron gas at the Ti-diffused BiFeO3/SrTiO3 interface
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Ti 扩散 BiFeO3/SrTiO3 界面处的二维电子气
DOI：
10.1063/1.4926732
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发表时间：
2015-07-20
影响因子：
4
通讯作者：
Ikuhara, Yuichi
中科院分区：
文献类型：
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作者：
Chen, Chunlin;Lv, Shuhui;Ikuhara, Yuichi
具有平移对称性破坏的氧化物异质结构通常会触发二维量子约束和相关的独特电子性质，而这些性质在体成分中是无法观察到的。特别感兴趣的是在两个绝缘体之间的异质界面上形成二维电子气体（2DEG），这为制造先进的电子设备提供了肥沃的土壤。在这里，我们结合原子力显微镜，透射电子显微镜和原子第一性原理计算来证明（100）BiFeO3/SrTiO3界面具有金属性质，并且在该界面产生2DEG。我们的研究结果还表明，由于极性不连续引起的电子重构以及由SrTiO3中的Ti离子扩散到BiFeO3的Fe位点引起的Ti价态的变化对异质界面上2DEG的形成至关重要。(C) 2015 AIP出版有限责任公司
Oxide heterostructures with the broken translational symmetry often trigger a two-dimensional quantum confinement and associated unique electronic properties that cannot be observed in bulk constituents. Particular interest is devoted to the formation of two-dimensional electron gas (2DEG) at heterointerfaces between two insulators, which offers a fertile ground for fabricating advanced electronic devices. Here, we combine atomic force microscopy, transmission electron microscopy, and atomistic first-principles calculations to demonstrate that the (100) BiFeO3/SrTiO3 interface takes on a metallic nature and a 2DEG is generated at this interface. Our findings also reveal that the electronic reconstruction due to the polar discontinuity and the variation in valence state of Ti arising from diffusion of Ti cations in SrTiO3 to Fe sites of BiFeO3 are critical to the formation of 2DEG at the heterointerface. (C) 2015 AIP Publishing LLC.