Physics Colloquium: Weilin Jiang, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboraty

Monday, September 12 2011 at 4:00 PM

Location: EP 209

TITLE: “Irradiation-Induced Defects and Their Processes in Single Crystals and Nanostructured Materials”

ABSTRACT: Radiation effects in solid materials have been an active topic of research for many decades. Greater efforts are being made both in experiment and theory due to increasing demands for materials that are resistant or susceptive to ionizing and displacing radiation. Robust radiation-resistant materials are needed for structural components of next-generation nuclear power systems and for long-term storage and permanent disposal of existing and future spent fuels. In addition, radiation-resistant electronic and magnetic materials are also explored for a variety of applications, including for space missions. On the other hand, novel radiation-susceptive materials are required for development of advanced radiation monitors, sensors and detectors.

This presentation consists of two portions. The first portion introduces the fundamental processes of energetic ions traversing in solids and the physical foundation for various quantitative methods of ion-beam analysis. In the second portion, some of the selected results from our study of single crystals (SiC, GaN, etc.) and nanostructured materials (SiC and Fe3O4) will be presented, including damage accumulation and amorphization, thermal and dynamic recovery of defects, behavior of implanted species, role of interfaces, and ion-beam modification of material properties.

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