Efe Ipek, Spaldin Nicola A, Gattinoni Chiara
Materials Theory, Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland.
J Chem Phys. 2021 Jan 14;154(2):024702. doi: 10.1063/5.0033897.
We investigate, using density functional theory, how the interaction between the ferroelectric polarization and the chemical structure of the (001) surfaces of bismuth ferrite influences the surface properties and reactivity of this material. A precise understanding of the surface behavior of ferroelectrics is necessary for their use in surface science applications such as catalysis as well as for their incorporation in microelectronic devices. Using the (001) surface of bismuth ferrite as a model system, we show that the most energetically favored surface geometries are combinations of surface termination and polarization direction that lead to uncharged stable surfaces. On the unfavorable charged surfaces, we explore the compensation mechanisms of surface charges provided by the introduction of point defects and adsorbates, such as water. Finally, we propose that the special surface properties of bismuth ferrite (001) could be used to produce an effective water splitting cycle through cyclic polarization switching.
我们使用密度泛函理论研究了铁电极化与铋铁氧体(001)表面化学结构之间的相互作用如何影响该材料的表面性质和反应活性。精确了解铁电体的表面行为对于其在催化等表面科学应用以及在微电子器件中的应用来说是必要的。以铋铁氧体的(001)表面作为模型体系，我们表明，能量上最有利的表面几何结构是表面终止和极化方向的组合，这会导致不带电的稳定表面。在不利的带电表面上，我们探索了通过引入点缺陷和吸附物（如水）来提供表面电荷的补偿机制。最后，我们提出铋铁氧体(001)的特殊表面性质可用于通过循环极化切换产生有效的水分解循环。
