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Chemistry Seminar Series 291 (10/12/18)

October 12, 2018 - 3:00pm

Hans Bechtel, Lawrence Berkeley National Laboratory

Abstract:

The Advanced Light Source (ALS) is a Department of Energy User Facility that provides spectrally broad and bright light for chemical analysis and imaging of natural and engineered materials. The infrared beamlines at the ALS take advantage of these source characteristics to perform label-free spectroscopic imaging of individual living cells, novel materials, and unique samples from the bottom of the ocean to the depths of space and everywhere in between.  Diffraction and the long wavelengths of infrared light have traditionally limited the spatial resolution of far-field infrared techniques to the micron scale. Synchrotron infrared nano-spectroscopy(SINS) circumvents this problem by focusing light onto a conductive tip of an atomic force microscope (AFM) scanning in nanometer proximity to the sample.  The conductive tip localizes the light in the near-field region of its apex, providing wavelength-independent spatial resolution limited only by the tip radius, which is typically < 25 nm. I will discuss the potential of SINS and highlight several investigations of nanoscale and surface phenomena that were previously impossible to study with other IR techniques. 

Flyer File: bechtel_hans_ccb_flyer.pdf