In our latest interview, AZoMaterials speaks with Rick Haasch, a senior research scientist at the Materials Research Lab at the University of Illinois, about his background in analytical chemistry, current research interests, and how the Materials Research Lab uses the Kratos AXIS Supra+ to support surface analysis developments.
Could you please introduce yourself and tell us about your background in Analytical Chemistry?
I am a Senior Research Scientist at the Materials Research Laboratory (MRL) at the University of Illinois. I received a B.S. in chemistry from Marquette University in 1982 and a Ph.D. in Analytical Chemistry from the University of Minnesota in 1990. Although I was a part of the Analytical Chemistry Division at Minnesota, the research in our group was closer to what is now known as Materials Chemistry. This background made me fit in quite well with the MRL community.
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The MRL fosters interdisciplinary research at the forefront of materials science. Can you tell us more about how the lab supports XPS and surface analysis research?
The XPS lab is part of the Surface Analysis Core, one of the ten research cores integrated within the MRL Facilities. At MRL, the lab supports XPS and surface analysis research by assisting users in data collection, training users in instrument operation and data processing, and educating the community through workshops and classroom lectures. In many cases, we collaborate with our XPS users, adding further value to the XPS research carried out at MRL.
The MRL houses cutting-edge instrumentation for surface analysis. Can you tell us more about these instruments?
The instrumentation of the Surface Analysis Core of the MRL follows the general theme of our facility, of multi-technique characterization. In addition to XPS, the Surface Core features stylus profilometry to measure film thickness and surface texture, time-of-flight secondary ion mass spectrometry (ToF-SIMS) for surface and in-depth composition analysis, accelerator-based methods using a 0.5 – 3 MeV Pelletron ion accelerator, and a local-electrode atom probe (LEAP). All are useful for the research of surface and thin films. ToF-SIMS uses an energetic focused ion beam directed at a specimen to remove material by sputtering. Secondary ions are then accelerated and separated according to their mass-to-charge ratio. The Pelletron accelerator utilizes a much more energetic focused ion beam directed at a specimen. Its main use is Rutherford Backscattering Spectrometry (RBS) and ion implantation. RBS is used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions, typically protons or alpha particles), impinging on a sample. Ion implantation is used in material research to study, for example, radiation damage of materials. Atom-probe tomography uses field evaporation of atoms from a needle-shaped specimen to generate 3-dimensional information at near-atomic resolution and to possess chemical sensitivity that can reach parts per million.
How does Kratos’ AXIS Supra+ instrument facilitate the center’s research needs?
The Kratos Supra+ generates very high-quality spectra in terms of both resolution and signal-to-noise. Its automation, together with large sample holders and a multi-position sample magazine, offers high-throughput analysis. Its capabilities include characterization of the surface characterization, near-surface, and below the surface using either monochromatic Al Kα or Ag Lα X-ray sources, angle-resolved measurements, and ion sputtering with atomic or cluster ion bombardment. The Supra+ is a go-to instrument for those who want to identify and qualify the chemical states of their material. With the system’s 2-dimensional imaging capability, we are also able to understand chemical variation at the surface.
You are hosting an upcoming XPS workshop alongside Kratos later this year. What are you looking forward to during the workshop and why is it important to hold sessions like these?
Workshops such as these are important in terms of fulfilling MRL’s missions of education and service through outreach. The MRL usually holds several workshops every year covering the range of our techniques.
During this workshop, I am looking forward to describing our XPS capabilities to our local research community and learning about their ongoing and future research projects. Our facility also benefits when we can gain feedback on how we can better serve the research community. It’s basically a win-win situation.
Your research interests involve using XPS, AES, and UPS to study the chemical and electronic properties of material surfaces and interfaces. What topics are you currently investigating?
My current research interests focus on the study of energy-related materials. I have recently been involved with collaborative projects relating to improving the performance and safety of lithium-ion and solid-state lithium metal batteries. These efforts are focused on increasing the capacity and lifetime of the batteries, as well as minimizing the catastrophic short-circuit failure of the batteries due to lithium dendrite formation. Other projects involve studying novel catalysts to facilitate green hydrogen production for zero-emission vehicles and reduction of NOx for pollution reduction and ammonia production.
You also serve as the editor-in-chief for the AVS Publication Surface Science Spectra. How does the journal help work towards increasing the availability of surface-sensitive data?
The initial focus of Surface Science Spectra (SSS) was to produce a database of X-ray photoelectron spectra that researchers and XPS practitioners could access. It was envisioned that the database should contain sufficient information regarding the specimen, instrument, and operating conditions so that the spectra could be properly interpreted and reproduced. Also, the spectra should be available not only in graphical form but also in digital form. These were very ambitious goals considering that the Journal’s first volume was published in 1992. In many ways, SSS was ahead of its time. SSS articles feature downloadable digital spectral datafiles with the above-mentioned metadata and are citable having both a journal citation and digital object identifier number. We are also adding more techniques to the Journal. Besides XPS, SSS currently publishes Auger electron and electron energy-loss data, ultraviolet photoelectron data, spectroscopic ellipsometry data and optical constants, ultraviolet-visible data, low-energy ion scattering data, and secondary-ion mass spectrometry data. We also publish Special-topic data collections. Current collections include higher-energy XPS data, data from materials for energy and the environment, and a SIMS collection of historic inorganic pigments.
What is next for you and the Materials Research Laboratory? Do you have any other exciting projects you are working on currently?
To compensate for a recently retired staff member, I am learning to operate the Pelletron ion accelerator and the second is a local-electrode atom probe. Hands-on experience with these instruments will help me guide our users in the utilization of RBS and LEAP in their research with the goal of enhancing their overall research experience. Knowledge in these instruments will also allow to me to form new collaborative research projects. I have also been invited to present a talk at the Brazil Vacuum Society meeting this November.
Where can readers find more information?
About Rick Haasch
Rick has authored or co-authored more than 200 publications and presentations in the areas of surface analysis, materials characterization, and materials chemistry. For more than 33 years, he has taught several hundred graduate students and postdocs about the use of XPS and Auger and given numerous invited lectures
on XPS and surface analysis techniques to research groups and materials science and chemistry classes at the University of Illinois.
Rick is a 40-year member of AVS and has recently served as an AVS Director (2018-2019) and as Secretary of the AVS Applied Surface Science Division (2009-2020). In 2010, he became Editor of the AVS journal Surface Science Spectra (SSS) and now serves as its Editor-in-Chief.
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