Friday, 1 November 2013, 12:30 PM, Physics 143
Electron Energy Loss Spectroscopy With High Energy and Spatial Resolution
Prof. Peter Rez, Department of Physics, Arizona State University
At ASU we have just taken delivery of a Nion aberration corrected electron microscope equipped with a monochromater that gives spectra with meV energy resolution. This represents almost an order of magnitude improvement in energy resolution in electron microscopy. Although the higher current density will make it easier to record fine structures such as multiplet splittings in the transition metal L23 white lines, lifetime broadening is at least 100 meV so it is unlikely that new features will be observed on inner shell edges. The improvement in energy resolution makes interesting new observations possible in the band gap region. Band onsets can now directly be recorded with greater precision and I shall show how color center peaks can now be observed. In principle it should be possible to even observe vibrations that are usually studied by IR and Raman, especially those due to stretching of bonds involving tightly bound hydrogen. Although the cross sections are quite large, greater than Carbon K shell cross sections, in practice we shall be limited by background both from zero loss tails and possibly multiple scattering of acoustic phonons.
Wednesday, 2 October 2013, 3:15 PM, Physics 481
Laser Induced Breakdown Spectroscopy for Hazardous Material Detection
Dr. G. Manoj Kumar, Advanced Center for Research in High Energy Materials, University of Hyderabad
Friday, 5 April 2013, 12:00 PM
Search for Superconductivity in the Iron-Tellurium System
Dave Gelting, UWM Physics Research Associate or
Dr. Prasenjit Guptasarma, UWM Physics Associate Professor
Friday, 22 February 2013, 12:00 PM
Electron-Optical Phase Shift and the Transport of Intensity Equation
Dr. Marvin Schofield, UWM Physics Post Doc
Friday, 25 January 2013, 12:00 PM
Non-Centrosymmetric Superconductors
Manoj Kumar Kashyap, UWM Physics Graduate Student