skip to content
 

Henslow Research Fellow (Girton College)

BSChem University of Michigan

BMus University of Michigan

PhD University of Cambridge

Electron Spectroscopy and Tomography for Quantitative Three-dimensional Chemical Imaging

My research focuses on spatially resolved spectroscopy and spectroscopic tomography in the electron microscope. Electron energy loss spectroscopy in the scanning transmission electron microscope (STEM-EELS) reveals composition as well as chemical bonding and oxidation state information – with nanometre to atomic spatial resolution. When combined with tomographic approaches, these techniques enable three-dimensional microstructural characterization. I am particularly interested in using electron tomography and spectroscopy to examine amorphous materials where conventional crystallographic approaches do not provide significant image contrast. In turn, these observations reveal assembly processes in materials such as metal-organic framework glass composites (in collaboration with T. Bennett).

I also use monochromated EELS to examine the optical properties of materials at ultraviolet, visible, and infrared energies, building off previous work in surface plasmons and the optical properties of metal nanoparticles.

 

llustration of electron spectroscopy and tomography used to disentangle the electronic structure of the surface (Ce3+) and the bulk (Ce4+) with sub-nanometer precision in a doped cerium oxide nanoparticle catalyst.

 

  • S. M. Collins, R. K. Leary, P. A. Midgley, R. Tovey, M. Benning, C.-B. Schönlieb, P. Rez, M. M. J. Treacy “Entropic comparison of atomic-resolution electron tomography of crystals and amorphous materials” Phys. Rev. Lett. 2017, Accepted.
  • S. M. Collins, S. Fernandez-Garcia, J. J. Calvino, P. A. Midgley “Sub-nanometer surface chemistry and orbital hybridization in lanthanum-doped ceria nano-catalysts revealed by 3D electron microscopy” Sci. Rep. 2017, 7, 5406. doi:10.1038/s41598-017-05671-9
  • S. J. Barrow, S. M. Collins, D. Rossouw, A. M. Funston, G. A. Botton, P. A. Midgley, P. Mulvaney “Electron Energy Loss Spectroscopy Investigation into Symmetry in Gold Trimer and Tetramer Plasmonic Nanoparticle Structures” ACS Nano 2016, 10, 8552-8563. doi: 10.1021/acsnano.6b03796
  • S. M. Collins, E. Ringe, M. Duchamp, Z. Saghi, R. E. Dunin-Borkowski, P. A. Midgley “Eigenmode tomography of surface charge oscillations of plasmonic nanoparticles by electron energy loss spectroscopy” ACS Photonics 2015, 2, 1628-1635. doi:10.1021/acsphotonics.5b00421
  • A. I. Carim, S. M. Collins, J. M. Foley, S. Maldonado “Benchtop electrochemical liquid-liquid-solid growth of nanostructured crystalline germanium” J. Am. Chem. Soc. 2011, 133, 13292-13295. doi:10.1021/ja205299w

Research Group

Telephone number

Email address