Speaker: Ondrej L. Krivanek, Arizona State University
Date & Time: March 3, 2016, 2:00 - 3:00
Location: Hennings 318
Local Contact: George Sawatzky
Intended Audience: Graduate
Aberration-corrected scanning transmission electron microscopes (STEMs) are now able to form electron probes as small as 0.5 Å in diameter, and they can image and spectroscopically analyze single atoms in-situ. Nion Co., has pioneered these advances, by developing the first aberration corrector that improved spatial resolution of an electron microscope to better than 1 Å, and later on by developing a new STEM that can acquire images and high quality spectra from single atoms in many different types of materials. More recently, we have introduced a monochromated STEM system for electron energy loss spectroscopy (EELS), which has made vibrational spectroscopy possible at an energy resolution better than 10 meV, and a spatial resolution of a few nm.
This seminar will review the basic principles behind the new developments, illustrate them with experimental results from a variety of materials, and discuss and illustrate especially inviting future directions.