MSE Seminar Series: John Unguris
Friday, April 27, 2012
1:00 p.m.-2:00 p.m.
Room 2110 Chemical and Nuclear Engineering Bldg.
301 405 5240
Imaging Magnetic Nanostructures with Spin-Polarized Electrons
Electron Physics Research Group
Imaging the magnetic structure in nanoscale devices, such as magnetic memory elements, or in magnetic materials, such as multiferroics, provides useful information about how these systems work (and occasionally fail). Lately, magnetic imaging has become even more challenging due to advances in lithography and processing. There is simply less magnetic material present and techniques with higher spatial resolution and sensitivity are required. We use Scanning Electron Microscopy with Polarization Analysis (SEMPA) to directly image the 3-dimensional magnetic structure with 10 nm resolution and monolayer sensitivity. In this presentation I will use a few measurement examples from magneto-electronics to describe some of the features (and problems) of the SEMPA technique.
About the Speaker
John Unguris is a Project Leader in the Electron Physics Research Group in the CNST. He received a B.S. in Physics from Carnegie Mellon University, and a Ph.D. in Physics from the University of Wisconsin. John initially joined NIST as a NRC Postdoctoral Research Associate investigating the application of electron spin measurements to various surface sensitive spectroscopies. Since then his research at NIST has focused on the development of techniques to measure the properties of magnetic nanostructures; in particular, spin sensitive electron microscopy. John has over 80 publications, is a frequent invited speaker at international meetings, and has helped organize numerous workshops and conferences on magnetism. He is a Fellow of the American Physical Society, and has been awarded a Bronze Medal from the Department of Commerce. John currently leads multiple projects investigating the fundamental physics of magnetic nanostructures.