Direct observation of X-ray induced Atomic Motion using STM combined with Synchrotron Radiation
Direct observation of X-ray induced Atomic Motion using STM combined with Synchrotron Radiation
复制标题
使用 STM 结合同步辐射直接观察 X 射线诱导原子运动
DOI：
10.1166/jnn.2011.3916
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
and M. Aono
中科院分区：
文献类型：
--
作者：
A. Saito;T . Tanaka;Y . Takagi;H. Hosokawa;H.Notsu;G .Ohzeki;Y .Tanaka;Y .Kohmura;M.Akai-Kasaya;T .Ishikawa;Y .Kuwahara;S.Kikuta;and M. Aono
在超高真空条件下，利用同步辐射扫描隧道显微镜（STM）系统，以原子级分辨率直接观测了Ge（111）-c（2 × 8）清洁表面上X射线诱导的原子运动。通过发展一种方法来合并X射线照射前后的STM图像，原子运动被可视化为跟踪图像。使用跟踪图像，原子迁移率被发现是强烈的表面上的缺陷的影响，但不依赖于入射的X射线能量，虽然它显然是依赖于光子密度。原子运动可以归因于表面扩散，这可能不是由于伴随电子跃迁的核心激发，而是X射线照射的热效应。晶体表面结构甚至可以在比常规已知的势垒更低的光子密度下断裂。这些结果可以在不久的将来提醒X射线研究在测量过程中样品损坏，同时提出新的应用的可能性。实验结果也表明了原位SR-STM系统的新的有效性。
X-ray induced atomic motion on a Ge(111)-c(2 × 8) clean surface at room temperature was directly observed with atomic resolution using a synchrotron radiation (SR)-based scanning tunneling microscope (STM) system under ultra high vacuum condition. The atomic motion was visualized as a tracking image by developing a method to merge the STM images before and after X-ray irradiation. Using the tracking image, the atomic mobility was found to be strongly affected by defects on the surface, but was not dependent on the incident X-ray energy, although it was clearly dependent on the photon density. The atomic motion can be attributed to surface diffusion, which might not be due to core-excitation accompanied with electronic transition, but a thermal effect by X-ray irradiation. The crystal surface structure was possible to break even at a lower photon density than the conventionally known barrier. These results can alert X-ray studies in the near future about sample damage during measurements, while suggesting the possibility of new applications. Also the obtained results show a new availability of the in-situ SR-STM system.