A5032390815- Semiconductor materials and devices
- Surface and Thin Film Phenomena
- Force Microscopy Techniques and Applications
- Advanced Surface Polishing Techniques
- Copper Interconnects and Reliability
- Electron and X-Ray Spectroscopy Techniques
- Metal and Thin Film Mechanics
- Polymer Surface Interaction Studies
- Block Copolymer Self-Assembly
- Nanofabrication and Lithography Techniques
- Microwave Engineering and Waveguides
- Diamond and Carbon-based Materials Research
- Molecular Junctions and Nanostructures
- Magnetic properties of thin films
- Integrated Circuits and Semiconductor Failure Analysis
- Silicone and Siloxane Chemistry
- Chemical and Physical Properties of Materials
- Advanced Chemical Physics Studies
- Synthesis and properties of polymers
- Advancements in Photolithography Techniques
- nanoparticles nucleation surface interactions
- Iron oxide chemistry and applications
- Advanced Materials Characterization Techniques
- Silicon Nanostructures and Photoluminescence
- Microwave and Dielectric Measurement Techniques
Texas State University
2000-2024
Lawrence Berkeley National Laboratory
1993-1998
University of California, Berkeley
1993-1998
We have studied the first monolayer of epitaxial iron oxide on Pt(111) with x-ray photoelectron diffraction and other methods. confirm a previously proposed superlattice model for this monolayer, but also conclude that grows as bilayer FeO(111) oxygen layer outermost, Fe-O interlayer distance is highly compressed relative to bulk FeO by about 50%, only one two possible domains forms due interactions between platinum.
We applied electron-scattering quantum-chemistry theory to investigate the origin of contrast in scanning tunneling microscopy images iron oxide grown on Pt(111). show that (a) image and surface topography are not directly related; (b) maxima occur over O positions for Pt tips Fe O-terminated tips; (c) short-range corrugation is always due ${p}_{z}$ orbitals, with a small but important contribution Fe; (d) state carriers most current located near Fermi level made mostly $3{d}_{z2}$ orbitals.
We have studied the growth of iron oxide films on Pt(111) using scanning tunneling microscopy. The system has been found to depend sensitively temperature and oxygen pressure used form oxide. As coverage is varied from below a monolayer multilayers approximately four or five layers thick, three different ordered structures are observed as well regimes in which appears disordered. For coverages ≤1 ML, FeO large lattice mismatch between platinum governs process. first structure occurs at unit...
Macroscopic CO diffusion on Ni(110) was found to be greatly impeded by surface contamination of just a few percent sulfur monolayer. The effect became even much more pronounced if the sample annealed at high temperatures. results can understood from consideration that S-covered steps effectively block with higher energy barrier.
The current status of photoelectron-diffraction studies surface structures is briefly reviewed, and several recent developments proposals for future areas application are then discussed. full-solid-angle diffraction data, together with simultaneous characterization by low-energy electron-diffraction scanning-tunneling microscopy, to epitaxial growth considered. Several new avenues that being opened up third-generation synchrotron-radiation sources also These include photoelectron from...
Self-assembled monolayers of n-octadecylamine (ODA-SAMs) on mica have been prepared and studied by contact jumping mode atomic force microscopy (AFM). Adhesion friction data show that the compactness spontaneously increases as they are allowed to ripen. Molecular packing can also be induced controlled mechanical perturbation exerted probe when getting into out intermittently. Under these conditions, defects vacancies aggregate giving rise detectable pinholes uniformly distributed in AFM...
Abstract Background Evidence-based and student-centered instructional methods hold the promise of transforming undergraduate STEM education simultaneously solving dual challenge workforce needs inequities within STEM. The Learning Assistant (LA) Model was created to reform curriculum, recruit teachers, inform discipline-based research. Numerous studies have shown positive impacts on students Assistants (LAs) in terms retention pass rates, learning outcomes, attitudinal shifts, emotional...
We have used atomic-force microscopy to measure the change in interfacial friction and adhesion between a tungsten surface bare or alumina-coated Si3N4 tips. These measurements been made aqueous solutions ranging pH from 2.2 8.2 absence of chemical mechanical dissolution oxide. Friction is observed vary with solution pH, specific manner which depends on influenced by composition interface. The maximum force tungsten/silicon nitride system occurs at 4.7. tungsten/alumina has frictional 6.6....
We report the successful sputter coating of microfabricated silicon cantilever and tip assemblies with high-quality titanium/titanium nitride (Ti/TiN) thin films using a technique that will be available to many researchers. demonstrate use pulsed mode reactive dc magnetron sputtering, adequate thermal budget, careful control titanium seed layer were key elements for producing usable coated cantilevers. This material takes advantage excellent adhesive properties Ti oxide intrinsically hard...
Silicon nanoparticles have been studied for a wide variety of applications including nanoelectronic, photovoltaic, and optoelectronic devices. In this work, silicon were synthesized by short-period annealing silicon-on-insulator substrates to temperatures ranging between 600 900 °C in argon gas at atmospheric pressure. Two different top layers deposited ion-beam sputtering onto oxidized substrates. The thinner 6 nm layer samples annealed 30 s periods while thicker 15 60 periods. For both...
Calixarenes of a variety molecular weights and with several different functional attachments have been studied as high resolution, contrast negative electron beam resists. In this article, results are presented for new type calixarene molecule to be used an resist. The differs from previous resists through the use bridging groups limit its conformational mobility by having only partial functionalization available phenol units allyl enhance resist sensitivity. Both sensitivity were measured....