Other Research Interests

I work closely with Dr. Peter Williams  in order to improve NanoSIMS instrumentation, e.g., we tested a new cesium ion source design on our NanoSIMS that has tiny 25nm spot sizes. We have a patent on this source design. Currently we are testing new duoplasmatron designs, and have been able to achieve 75 nm oxygen beam sizes.

I have developed key measurement protocols for nanoscale imaging and high-precision isotopic data using the NanoSIMS. I have considerable experience in a variety of other NanoSIMS applications in collaboration with ASU faculty and researchers elsewhere.

Geochemistry

  • Lithium diffusion in zircons, olivine
  • Aluminum contents in experimental zircons
  • Rare earth element diffusion in pyroxenes, sanidines, zircons
  • H contents in silicate inclusions within mantle diamonds

Environmental

  • Elemental and isotopic heterogeneities in foram shells
  • Sulfur isotopes in individual aerosol particles
  • Trace element reconnaissance study on black oil shale

Microbiology

  • Characteristics of the blood-brain barrier in honeybees
  • Carbon isotopic labeling of cyanobacteria boring into calcite and dolomite
  • Labeled ciliate (bacteria) and prymnesium (flagellated algae) to understand nutrient intake
  • Clay-microbial interactions using trace metals
  • Nitrogen cycling in extreme environments, e.g., the hotsprings in Yellowstone National Park
  • The process of formation of thylakoid membranes in cyanobacteria
  • Mapping phosphorus in biomagnetite

Material Science

  • Characterization of materials  such as doped Si wafers and textured solar cells
  • Mapping inter-grain boron in steel