Developing and exploiting new experimental methods, detectors, and physics approaches in synchrotron materials science to study the structure and chemical nature of diverse materials, in partnership with Industry, National Labs, and University researchers. In particular for soft x-ray absorption spectroscopy developing specialized electron and fluorescence yield detectors; emphasizing imaging and high-throughput to measure structure and chemistry: (1) on the scale ranging from atomic to tens of nanometers, particularly for low concentrations of materials; (2) at the surface of individual nanoscale entities such as nanotubes and nanoparticles; (3) at specific locations; e.g., an interface in a multilayer device; and (4) under relevant conditions, e.g., temperature and pressure, that the material will be subjected to in use. Materials currently under investigation include organic and inorganic electronics, model catalyst systems, polymer surfaces and their interfaces, hard disk lubricant chemistry, self-assembled monolayers, and high temperature superconductors.
Figure 1(left): Near Edge X-ray Absorption Fine Structure was used to investigate the chemical bonding mechanism of a Ti oil additive (10 ppm) with the metal surface of actual rocker arms from the engine tests. Results enable us to postulate that Ti provides anti-wear enhancement through the formation of FeTiO3 on the engine surface.
Figure 2(left): Focusing multi-layer wavelength dispersive carbon fluorescence detector for nearly background free soft x-ray absorption spectroscopy of insitu reaction intermediates inside working catalysts.; Figure 3(right): Near Edge X-ray Absorption Fine Structure was used to establish structure (molecular orientation, chemistry, and coverage) function (carrier mobility) in organic semiconductors as a function of thermal processing for rational material optimization.
Postdoctoral Research Opportunities in My Group:
Awards and Honors
Materials Measurement Science Division
Synchrotron Methods Group
2003-present: Group Leader, Synchrotron Methods, Ceramics Division, NIST
Ph.D., Physics, Stony Brook University, 1984
Phone: (301) 975-5972