Screening of ferroelectric domains on BaTiO3(001) surface by ultraviolet photo-induced charge and dissociative water adsorption
Screening of ferroelectric domains on BaTiO3(001) surface by ultraviolet photo-induced charge and dissociative water adsorption
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DOI：
10.1063/1.4748330
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发表时间：
2012-08
影响因子：
4
通讯作者：
J. Wang;B. Vilquin;N. Barrett
中科院分区：
文献类型：
--
作者：
J. Wang;B. Vilquin;N. Barrett
利用从镜面电子显微镜到低能电子显微镜的转变，测量了BaTiO_3(001)单晶在紫外光照射下，水解离吸附前后相反极化铁电畴的表面电势对比度。光生自由电荷载流子和水的解离吸附是表面极化电荷的有效屏蔽机制。屏蔽率主要由漂移控制，而无紫外光时的弛豫主要由热扩散驱动。表面化学在表面电荷动力学中起着重要的作用。
The surface potential contrast between oppositely polarized ferroelectric domains of a BaTiO3(001) single crystal under ultraviolet (UV) illumination before and after the dissociative adsorption of water is measured using the transition from mirror electron microscopy to low-energy electron microscopy. Both photo-generated free charge carriers and dissociative adsorption of water are effective screening mechanisms of the surface polarization charge. The screening rate is dominated by drift, whereas the relaxation in the absence of UV light is driven by thermal diffusion. Surface chemistry plays an important role in the surface charge dynamics.