(0001) Interfaces between M2O3 corundum oxides (M = Al, Ti, V, Cr, Fe).
(0001) Interfaces between M2O3 corundum oxides (M = Al, Ti, V, Cr, Fe).
复制标题
DOI：
10.1016/j.susc.2018.08.015
复制
发表时间：
2019-01-01
期刊：
影响因子：
1.9
通讯作者：
Noguera, C.
中科院分区：
文献类型：
--
作者：
Le, H. -L. T.;Goniakowski, J.;Noguera, C.
氧化物/氧化物界面的结构质量、它们的化学性质以及它们的电子态性质是新的有前途的应用的关键特性，并且需要对其基础理解的不断进步。为此，我们对刚玉结构中结晶的简单金属氧化物和过渡金属氧化物之间的一系列 (0001) M2O3/M'O-2(3) 界面（M、M' = Al、Ti、V、Cr、Fe）进行了理论研究。我们的 DFT + U 结果揭示了界面电荷重新分布的两种性质不同的机制：Ti2O3/V2O3 和 Ti2O3/Fe2O3 接触处发生的界面氧化还原反应，以及沿着阴离子-阳离子键的较弱的电子转移，其遵循所有界面处两种构成氧化物之间的离子性差异。与 sp 半导体之间的界面不同，能带弯曲不会传播到一两个原子层之外。更一般地说，我们的结果表明，界面电子结构的性质及其形成的能量可以与相应块体氧化物的性质紧密相关，从而为设计所需特性的氧化物/氧化物界面提供了宝贵的工具。
The structural quality of oxide/oxide interfaces, their chemistry, and the nature of their electronic states are critical properties for new promising applications and require continuous advances in their fundamental understanding. To this goal, we have performed a theoretical study of a series of (0001) M2O3/M'O-2(3) interfaces (M, M' = Al, Ti, V, Cr, Fe) between simple and transition metal oxides crystallizing in the corundum structure. Our DFT + U results reveal two qualitatively different mechanisms of interface charge redistribution: an interfacial oxidation-reduction reaction occurring at Ti2O3/V2O3 and Ti2O3/Fe2O3 contacts, and a much weaker electron transfer along anion-cation bonds which follows the difference of ionicity between the two constituting oxides at all interfaces. At variance with interfaces between sp semiconductors, the band bending does not propagate beyond one or two atomic layers. More generally, our results show that the nature of the interface electronic structure and the energetics of its formation can be tightly linked to the properties of the corresponding bulk oxides, thus providing a precious tool for designing oxide/oxide interfaces of required characteristics.