Ulrike Diebold - US grants

The objective of this Faculty Early Career Development (CAREER) project, supported in the Analytical and Surface Chemistry Program, is the characterization of the surface chemistry, structure, and defects of transition metal oxide surfaces that have broad scientific and technological application. Professor Diebold and her undergraduate and graduate students at Tulane University will use a range of surface characterization techniques in this work including scanning tunneling microscopy, X-ray photoelectron spectroscopy, ion scattering spectroscopy, and thermal desorption spectroscopy. The aim of this CAREER research project is to probe the formation of defects and the reactivity of these oxide surfaces at the atomic level to establish a foundation for understanding the chemistry that occurs at these surfaces. Educational thrusts beyond involvement of students in this research involve the development of a new surface science course to complement the laboratory experience and an outreach and mentoring program centered around the establishment of a mobile scanning tunneling microscopy laboratory. Transition metal oxide surfaces are used in the fabrication of gas sensors, catalysts, coatings for corrosion protection, and environmental degradation systems. Professor Diebold and her students at Tulane University will apply several surface spectroscopic methods that provide atomic scale spatial resolution to the study of the chemistry, structure, and defects of transition metal oxide surfaces with support of this CAREER research project. The chemistry that occurs at the surfaces of these oxides is highly dependent on the structures that exist there. Knowledge of how these structures control these chemical reactions will be produced by this work. This hands-on experimental program will have a positive educational impact on the undergraduate and graduate students working on this project. Portable scanning tunneling microscopy experiments and other surface science experiments will be developed to bring the excitement of this work to high school students in the New Orleans and Mississippi Delta areas. This activity will raise these students' awareness of the excitement that can be experienced in a scientific career.

This research project, supported in the Analytical and Surface Chemistry Program, examines the surface structure, defect structure, and surface chemistry of the semiconducting metal oxides TiO2, SnO2, and ZnO. Using scanning probe microscopy, coupled with UHV electron spectroscopic methods, a detailed understanding of the effects of surface and defect structure on the surface chemistry of these important materials is obtained. Professor Ulrike Diebold and her group in the Department of Physics at Tulane University are applying this information to the development of novel gas sensing devices.

High temperature semiconducting oxide sensors are used in a variety of gas sensing and monitoring applications. The detailed understanding of the surface structure and surface chemistry of these oxide materials is crucial to the design of robust sensors in these applications. Professor Diebold's studies of the surface structure and chemistry of this class of materials is providing this information and understanding.

With support from the Major Research Instrumentation (MRI) Program, Tulane University will acquire a growth/preparation apparatus for nanoscale and materials science. The new setup will combine a plasma source for non-invasive surface cleaning with thin film deposition equipment (physical vapor deposition, plasma-assisted vapor deposition, pulsed laser deposition) and basic in-situ characterization facilities (RHEED and XPS). The primary users will be researchers from Tulane University and Xavier University of Louisiana.

This apparatus will be used for the synthesis of a wide variety of magnetic catalytic, biocompatible, nanoscopic and structural materials, and will play a key role in integrating Tulane's and Xavier's materials synthesis and advanced surface characterization programs. It will also enhance instruction through research training of undergraduate, graduate, and post-graduate students; through implementation in several courses; and as a hands-on component in outreach programs.

With the support of the Analytical and Surface Chemistry Program, Professor Diebold and her coworkers in the Department of Physics at Tulane University are studying the surface chemistry of well characterized oxide surfaces. Using scanning tunneling microscopy, photoemission spectroscopy, and adsorption studies, the geometric and electronic structure of SnO2, In2O3, and ZnO surfaces are being examined. Focus of the work is on the structural and chemical properties of oxide nanobelts of these materials formed under certain conditions. Both synthesis and characterization of these nanobelt materials is carried out. Adsorption and reaction of small molecules on these surfaces is also examined.

The surface properties of nanoscale oxide materials are the focus of this research project supported by the Analytical and Surface Chemistry Program. Using scanning probe microscopy and photoemission methods, Professor Diebold and her collaborators are examining the detailed geometric and electronic structure of tin, indium, and zinc oxide surfaces, particularly in morphologies exhibiting nanobelt structures. The adsorption and reaction of small molecules on these surfaces is also examined. Information from these studies will be of use in the understanding of catalytic processes and nanomaterials synthesis methods.

0959393
John

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."

The proposal addresses Tulane University's request for a high resolution field-emission transmission electron microscope (FE-TEM) to complement its existing capabilities in electron microscopy and bring these capabilities to address the research needs of the university and academic researchers in the region. Tulane University operates an Electron Microscopy Facility as part of a centralized Coordinated Instrumentation Facility (CIF) (http://www.tulane.edu/~cif/) that was established in 1991 with the intent to maintain, manage and operate high priced instrumentation across the University. The electron microscopy facility is well-staffed by an excellent electron microscopist (Dr. Jibao He) who will provide training, participate in data interpretation, and maintain the instrument. Intellectual Aspects: The proposed TEM will be used to carry out a wide variety of research projects and to enhance the research resources available for new faculty across a range of scientific and engineering disciplines. There are 3 principal investigators and 6 senior investigators who will directly benefit from access to a high quality instrument. V. John will use the instrument for a variety of projects involving the self-assembly of lipid and surfactant systems to tubular liposomes and gel microstructures. S. Grayson's research related to dendrimers and macromolecules, T. Mandal's research in polymer nanoparticles related to drug delivery, T. Ahsan's project in stem cell characterization, and D. Khismatullin's research in cell cytoskeletal characterization, N. Pesika's research in biomimetic adhesive materials, and J. Wickramarajah's research in self-assembled porphyrin based materials, are all examples of projects in soft materials that will tremendously benefit from the use of high-resolution cryogenic imaging techniques for a fundamental understanding of underlying phenomena. U. Diebold's research in sub-surface microstructures in semi-conducting materials, Z. Mao's research in superconducting and magnetic thin films, N. Pesika's research in anisotropic quantum dots, and V. John's research in ceramics templated in self-assembled systems are examples where high-resolution TEM at the sub-nanometer scale will help understand the growth characteristics and properties of inorganic materials. The relatively recent advent of Field-Emission TEM providing tremendous increases in beam energy, brightness and coherence makes imaging at such resolutions and in such difficult-to-image systems possible. This proposal represents Tulane's efforts to bring its well-run electron microscope facility to a state-of-the-art facility conducting forefront research in an inherently interdisciplinary setting.