Speaker: Lin Zhou, Associate Scientist with the Division of Materials Science and Engineering at Ames Laboratory
Title: Applications of TEM Imaging, Analysis and Electron Holography to Alnico Permanent Magnets
Abstract: The Transmission electron microscope (TEM), with its many different configurations for imaging, diffraction and microanalysis, has become an indispensable tool for structural characterization of materials at nanoscale. Aided by aberration correction, the image resolution can nowadays surpass the one-Ångstron level and offers many exciting possibilities for the discovery, exploitation of novel materials, which are dependent on precise control of structure and chemistry. In this presentation, various TEM techniques have been used separately or in tandem in our collaborative studies of alnico permanent magnets to reveal the role of chemistry and heat-treatment conditions that impair the property of the final material. A breakthrough on the coercively of alnico was achieved by structural fine tuning.
Bio: Zhou received her Materials Science and Engineering Ph. D. in 2006 from Arizona State University, and then worked in the Physics Department as an assistant research scientist until she joined Ames Lab in 2012. She is currently an associate scientist in Ames Lab and an adjunct faculty of Materials Science and Engineering department at Iowa State University. She also provides scientific oversight on staff/postdocs and instruments in the Sensitive Instrument Facility in Ames Lab. Her research focuses on understanding structure-property relationship down to atomic level, as well as exploring mechanism and dynamic of phase transitions, induced by heat/cooling, magnetic field, electric biasing, and mechanical force, using advanced in situ electron-beam related techniques. The materials systems she is interested in include magnetic alloys, two-dimensional materials, ferroelectric oxides and semiconductor thin films.
MSE Seminar Host: Alan Russell