Ultimate surface sensitivity with LEISS, using the PHOIBOS analyzer.
Viktor Takáts, Attila Csik, Jòzsef Hakl, Kálmán Vad, Diffusion induced atomic islands on the surface of Ni/Cu nanolayers, Appl. Surf. Sci. 440, (2018) 275 – 281. Read the paper here.
A known challenge in surface science is obtaining spectroscopic data from the topmost atomic layer, since methods like XPS always “see” parts of the bulk material. A very powerful technique to gain information form the surface layer is the scattering of low energy ions (LEISS/ISS), which can be detected by a hemispherical analyzer like SPECS PHOIBOS. Due to its bipolar power supply, the PHOIBOS analyzer can be used as a multi-method tool to detect both photoelectrons and scattered ions, even simultaneously in a step-by-step manner.
A very impressive demonstration on the capabilities of LEISS is shown in this paper of Viktor Takáts et al. In their work, they follow diffusion processes on grain boundaries of Ni/Cu nanolayers with various in-situ techniques including LEISS. They were able to reveal diffusion constants of fast atomic motion processes at low temperatures. Although mass resolution is an inherent challenge for LEISS measurements, this work nicely shows that even neighboring elements in the periodic table of elements can be quantified.
Dynamic processes at surfaces are of high importance for a variety of research areas. Surface diffusion along grain boundaries can strongly influence the properties of microelectronics or have major influence in the activity and selectivity of catalysts. The paper of Viktor Takáts and colleagues is a good example how the versatility of SPECS PHOIBOS hemispherical analyzer can support your research by approaching research questions with different techniques using the same equipment.
A powerful but cost-effective solution for LEISS excitation is the focused, scannable ion source IQE12/38 with its COSCON SIS power supply, it is fully software integrated into SpecsLab Prodigy. The addition of this source into existing XPS systems with PHOIBOS analyzers immediately allows the use of a with the push of a button.