Volume 77, Issue 8, August 2006
Index of content:
- CONDENSED MATTER; MATERIALS
Instrumentation and analytical methods of an x-ray photoelectron spectroscopy–scanning tunneling microscopy surface analysis system for studying nanostructured materials77(2006); http://dx.doi.org/10.1063/1.2221539View Description Hide Description
The design and performance of an x-ray photoelectron spectroscopy (XPS)–scanning tunneling microscopy(STM)surface analysis system for studying nanostructured materials are described. The analysis system features electron spectroscopy methods (XPS and Auger electron spectroscopy) in addition to a variable temperature STM. With the analytical methods of the system, surface chemical analysis as well as surface morphology down to atomic resolution can be obtained. The system also provides facilities for sample cleaning,annealing, gas dosing, depth profiling, and surface modifications by sputtering and evaporation. Controlled gas exposures from ultrahigh vacuum to atmospheric pressures in the adjustable temperature range of can be carried out in different chambers. A fast entry air lock allows the transfer of samples and STM tips into the system without air exposures. The surface analysis system uses a common sample holder in all five chambers which are independently pumped and separated from each other by gate valves. Thus, it is possible to make all sample preparations and experiments in situ under well-defined conditions as illustrated by the formation and characterization of strained, self-assembled nano-oxides on Cu(100).
Design of a UHV-compatible rf plasma source and its application to self-assembled layers of nanoparticles77(2006); http://dx.doi.org/10.1063/1.2336192View Description Hide Description
A compact, versatile, and simple rf plasma source with capacitive coupling compatible to ultrahigh vacuum (UHV) requirements was designed and built to allow sequences of sample surface modification in plasma and surface preparation and analysis in vacuum without breaking the vacuum. The plasma source was operated at working pressures of less than 1 to a few millibars. Sample transfer to UHV was performed at pressures around . For easy integration into an existing UHV setup, the sample recipient and transfer system were made to accept standard commercial sample holders. Preliminary experiments were performed by exposing monolayers of colloidal nanoparticles to oxygen and hydrogen plasmas. The structural and chemical effects of the plasma treatments were analyzed with scanning electron microscopy and x-ray photoelectron spectroscopy.