With this award from the Chemistry Research Instrumentation: Multi-user (CRIF:MU) program, Professor Kerry Hipps and collaborators from Washington State University will upgrade spectroscopic instrumentation in the scanning probe microscopy facility that includes an ultra high vacuum scanning transmission microscope (UHV STM). The instrumentation will be upgraded with addition of a reverse-view grid optics for low-energy-electron diffraction (LEED) and Auger electron spectroscopy (AES), sample preparation chamber, preparation chamber pumping and gauging as well as other accessories. The award will enhance research training and education at all levels, especially in areas of study such as (a) structure and electronic properties of self-assembled systems, (b) surface defects and trap states in semiconductor nanoparticles, (c) analysis of organic nanostructures and photoconductivity studies, and (d) fundamental electronic properties of polymer/metal and bimetallic interfaces.
Ultra high vacuum scanning transmission microscopy is an analysis method for the study of surfaces on an atomic scale providing images that supplement other well-known vacuum analysis techniques. Scanning electron microscopes, like the one upgraded under this award, allow chemists to probe the structure of materials with extraordinarily high spatial resolution and with additional chemical and electronic characterization capabilities. This level of detail is especially needed when probing the chemical and physical properties of nanoscale materials, where the chemical heterogeneity changes at precisely these length scales. Without this level of detail, the progress towards new kinds of nanoscale materials will be made much more slowly. The addition of the low-energy electron diffraction (LEED) capabilities will enhance the determination of the surface structure of crystalline materials by bombardment with a collimated beam of low energy electrons; the diffracted electrons are generally observed as spots on a fluorescent screen. In Auger electron spectroscopy, energetic electrons emitted from an excited atom are analyzed to provide information on surfaces. The infrastructure made available with this grant will be used in teaching and training a broad range of young scientists in important, cutting-edge, experimental methods.
Intellectual Merit: We upgraded of an existing Scanning Probe Microscopy (SPM) Facility housed within the Chemistry Department at Washington State University. The original equipment for this facility was purchased with funds provided by NSF, by the Murdock Foundation, and by Washington State University. This facility has been in operation for 23 years and has served the needs of more than 11 faculty research groups in areas as diverse as agronomy, biochemistry, chemistry, physics, and Materials Science and Engineering. This center now houses an XPS analytical system, three scanning probe microscopes for ambient, solution, and controlled atmosphere studies, a 20 year old fixed temperature UHV system, and a new variable temperature ultra high vacuum preparation-analysis system. It is this new system that was purchased with the NSF funds reported here. This equipment upgrade allowed us to expand the range of problems that can be studied by SPM at Washington State University. It positions the department of Chemistry and the multidisciplinary program (Physics, Chemistry, and Engineering) in Materials Science and Engineering to better attract students and faculty and provides much needed facilities for ongoing and evolving research in nanotechnology. The upgrade added critical surface analysis and sample preparation capabilities to our existing variable temperature scanning tunneling microscope (STM). All of the modifications are housed in a new sample preparation chamber that is attached to a high resolution STM through an isolation valve and transfer system. This arrangement will also allow stand alone studies of LEED and Auger spectroscopy with minimal interference to ongoing STM studies. The LEED and Auger capabilities were also provided as part of this proposal. Applications include studies of organic nanostructures, electronic states of adsorbates and the influence of the substrate and co-adsorbates. In addition, self-assembled surface structures, the interaction of steady visible and UV light with surface structures, and electronic and structural properties of composite materials for the electronics industry will be better understood because of studies conducted with this new equipment. Broader Impacts: The broader impacts of this acquisition are manifold. The instrumentation is used in interdisciplinary work in materials science, physics, and in chemistry. It is being integrated into the training of approximately 15 graduate students and 10 undergraduates each year. Females and minorities will be directly introduced to nanotechnology and surface analysis methods through the use of this instrumentation. The existing facility is an integral part of both our materials science core PhD curriculum and a Materials Science Research Experience for Undergraduate program. An African-American student, who is also an NSF graduate research fellow, was able to complete his PhD only because this new upgrade was available. A different African-American student completed his NSF REU summer experience working with this instrumentation The facilities are extremely helpful in attracting new Physical Chemistry and Materials Chemistry faculty (searches are underway). The application of this equipment may have significant impact in the areas of Solar Energy Conversion, Fuel Cell Efficiency, Self-assembled Functional Materials, Laser Optics, Molecular Electronics, Electronic Composites, and Optoelectronics.
