Hard X-ray beam damage study of monolayer Ni islands using SX-STM

Abstract

X-ray beam-induced damage in nanoscale metal islands was investigated. Monolayer-high Ni islands were prepared on a Cu(111) substrate. High brilliance X-rays with photon energies between 8.45 and 8.85 keV illuminated the sample for about 11 hours. In order to track changes in the morphology of the islands, the synchrotron X-ray scanning tunneling microscopy (SX-STM) technique was utilized. The result shows that X-ray illumination onto Ni islands does not induce noticeable damage. The study demonstrates that local beam-induced changes can be studied using SX-STM.

X-ray Assisted Scanning Tunneling Microscopy and Its Applications for Materials Science: The First Results on Cu Doped ZrTe3

“…As shown in Figure 2a, during an SX-STM experiment the convoluted tip current is first fed into a lock-in amplifier (typically locking at a chopping frequency of 3 kHz or higher) and the output of LIA is directly proportional to the X-ray induced current signal. The tip current is then fed into a topological filter to cut off the high frequency signal and yield I tunneling , which is then fed into a feedback loop of an STM controller [21,22]. Moreover, an additional LIA can be used to record the signal originating from a sample simultaneously.…”