Luisa A. Dempere - US grants

Technical Summary:

X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS, respectively) provide information on chemical composition, chemical states, and electronic properties of surfaces and interfaces, which are critical to assist the understanding and further development of materials for a broad range of applications. The UPS capability coupled with the C60 ion sputtering source further expands the instrumentation capability to 'soft materials' such as organic, polymeric, and biological materials, which have received great scientific interests in recent decades. Examples of current NSF sponsored projects at the University of Florida that will greatly benefit from this instrument include: (1) characterization of organic-based semiconductors and interfaces for electronic and optoelectronic applications; (2) surfaces and interfaces of metal phosphonate and cyanometallate materials; (3) molecular approaches to directional growth of nanostructures for nanoelectronics; (4) microstructure-informed design methodology for advanced magnesium alloys; (5) graphene and other carbon-based materials and interfaces; (6) self-assembled colloidal nanoparticles for magnetic/biosensing applications. The Major Analytical Instrumentation Center (MAIC) is a user facility providing analytical microscopy and spectrometry instrumentation support to all disciplines at the university and the surrounding community. The state-of-the-art XPS/UPS instrument requested in this proposal replaces a 25-year-old XPS system, which not only accelerates the progress in various research programs through the vastly increased efficiency, but also provides new information through spatial imaging, high resolution chemical profiling, and vast expansion of the realm of materials to be characterized. The broader impacts of this instrumentation are also realized through a number of educational and outreach activities at the University of Florida and beyond.

Non-Technical Summary:

The advancement of many modern technologies, such as various energy solutions (storage, conversion, and conservation), nanotechnology, electronics and photonics, biomaterials and biotechnology, and transportation, rests upon the fundamental understanding of surfaces of the relevant materials and/or interfaces between different material components. One of the most informative surface analytical techniques is the x-ray or ultraviolet photoelectron spectroscopy (XPS and UPS, respectively), in which an x-ray or ultraviolet light is shone on the targeted materials and the types of atoms and the local chemical environment and physical properties of these atoms in the material near the surface are revealed by analyzing the energy of electrons ejected from the material surface. Buried material interfaces can also be probed when combining XPS/UPS with appropriate material deposition or removal techniques. The state-of-the-art XPS/UPS instrument requested in this proposal replaces a 25-year-old XPS system at the Major Analytical Instrumentation Center (MAIC), a user facility at the University of Florida which hosts an array of analytical instrumentation for the study of various types of materials. The new instrument provides vastly increased efficiency, new information through spatial imaging, higher energy resolution, and vast expansion of the realm of materials to be characterized. Furthermore, the new instrument provides unique opportunities for the cross-disciplinary research training and education of many graduate and undergraduate students, as well as opportunities for outreach to K-12 students and teachers and the general science and engineering community.

Non-Technical: This research contract centers on the acquisition of a new high-resolution electron probe microanalysis system with an integrated electron backscatter diffraction detector. This instrument will be the only one in the US and only one of three in the world with the capability of performing simultaneous crystallographic and chemical mapping at the sub-micron scale, and will permit trace elemental analysis with superb accuracy in a user-friendly environment. The instrument will have regional and international accessibility making it a multi-use, multi-institutional piece of state-of the-art equipment. This research program brings together a unique set of 15 researchers from 7 Florida state universities (University of Florida, University of North Florida, Florida State University, Florida A&M University, University of Central Florida, Florida International University and University of South Florida) that have one commonality: the need to understand the connection between chemistry and structure at the sub-micron scale. The central theme of this instrumentation program with regards to teaching, education and outreach is lowering institutional barriers. A multi-pronged approach has been developed to execute this objective: 1) a remote access system, 2) K-12 education modules developed for teachers to help them integrate microscopy into their classroom curricula, 3) partnerships with the on-campus NSF REU program to expose talented undergraduates to advanced microscopy techniques, where selection will be based on talent and focused on increasing diversity of women and underrepresented groups, 4) continuing education programs, and 5) strategic partnerships with 2 minority serving institutions and 5 emerging Hispanic serving institutions provide fertile ground and access to underrepresented groups to increase the impact of the proposed education and outreach initiatives.

Technical: This electron probe microanalysis system produces a small spot size with high spatial resolution on the nanometer scale. The uniqueness of the instrument can be highlighted in its use in transforming research in 4 critical areas. These areas include: 1) revealing the fundamental connections between microstructure, chemistry and microtexture in light element structural alloys, 2) understanding chemical diffusion in metallic and oxide systems to develop a unified theory for thermal diffusion while gaining deeper insight into the relationship between chemistry and structure in functional oxides, and 3) mapping phase boundaries in nanoprecipitation dispersion strengthened systems, and 4) robust and accurate measurement of minor and trace element with high spectral resolution needed for geological materials. The key features of this instrument that create maximal impact are the ability to perform: 1) trace elemental analysis with superb accuracy in a user-friendly environment, 2) quantitative mapping of light elements to show their true concentration distribution and advanced spectral resolution to avoid peak overlaps that are common with light elements, 3) fine-scale microstructural, chemical and crystallographic analysis, and 4) research and teaching by logging in online to remotely view and control the instrument.

This award from the Major Research Instrumentation Program supports the acquisition of a Zeiss Xradia 620 Versa Computed Tomography (Versa nanoCT) system at the University of Florida, where it will be accessible to students, researchers, industrial partners, and museum personnel. The Versa nanoCT is a non-destructive characterization tool that provides nano-scale 3D imaging of internal and external features of organic and inorganic specimens. The equipment?s versatility allows it to impact a variety of scientific fields, including materials science, vertebrate zoology, and biomedical engineering. The acquired data will be shared through open source networks and field-specific databases to reach researchers around the world and enable broad-scale data research initiatives. Additionally, the data collected will be implemented in graduate, undergraduate, and high-school education, 3D machine learning development, and public engagement activities via virtual museum collections.

The acquisition of a Zeiss Xradia 620 Versa Computed Tomography (Versa nanoCT) system introduces new research opportunities by providing nondestructive, 3D imaging that is essential for identifying critical microstructural or morphological features to fundamental material or biological processes, respectively. Additionally, the unique features of the Versa nanoCT, including the high X-ray source flux, 40X magnification optics, diffraction contrast tomography (LabDCT) and phase contrast, provide essential information that are typically unavailable outside of synchrotron facilities. The Versa nanoCT enables and supports research in three critical areas: (1) elucidating fundamental microstructure-property relationships to control the strength of structural metals and ceramics, (2) archiving morphological diversity to better understand the processes that drive the diversification of living and extinct organisms, and (3) monitoring cell-material interactions to guide tissue generation. The instrument also supports educational initiatives at the graduate, undergraduate, and high-school level, support data support for 3D machine learning initiatives, and engage the public through outreach at the Florida Museum of Natural History (FLMNH) Education and Exhibition Center.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.