Defect structure of nonstoichiometric CeO2(111) surfaces studied by scanning tunneling microscopy
Defect structure of nonstoichiometric CeO2(111) surfaces studied by scanning tunneling microscopy
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DOI：
10.1103/physrevlett.79.4222
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发表时间：
1997-11-24
影响因子：
8.6
通讯作者：
Briggs, GAD
中科院分区：
文献类型：
--
作者：
Norenberg, H;Briggs, GAD
用扫描隧道显微镜（STM）研究了非化学计量比CeO_2（111）的表面结构。通过使用极小的隧穿电流，有可能获得有史以来第一次报道的这种氧化物的原子分辨图像。STM成像是可能的，在样品偏置电压在-2和-3.5 V之间。比较这与二氧化铈的能带结构，我们声称，图像对比度的主要贡献的结果从最上层的氧。在RT表面上的主要缺陷类型是三角形的形状，并包含三个氧空位。在衬底温度为500摄氏度的高温STM揭示了表面上的氧空位的排列。的缺陷形状与以前的能量计算定性一致。
The surface structure of nonstoichiometric CeO2(111) has been studied by scanning tunneling microscopy (STM). By using extremely small tunneling currents it was possible to obtain the first ever reported atomically resolved images of this oxide. STM imaging was possible at a sample bias voltage between -2 and -3.5 V. Comparing this with the band structure of ceria we claim that the main contribution to the image contrast results from oxygen in the topmost layer. The dominant defect type on the surface at RT is of triangular shape and contains three oxygen vacancies. Elevated temperature STM at a substrate temperature of 500 degrees C revealed an alignment of oxygen vacancies on the surface. The defect shapes are in qualitative agreement with previous energy calculations.