Abstract

Dr. Petra Reinke
Materials Science and Engineering
University of Virginia

Monday, March 24, 2008
Wilsdorf Hall, RM 101
4:00 PM*

"Designing Nanoscale Structures and Building Blocks With Surface Templates"

ABSTRACT:

In nanotechnology we explore lengthscales and phenomena, which are characteristic for the transitional regime between a solid and a single atom. This size regime offers an incredible wealth of intriguing possibilities, and quantum dots and nanotubes are just two examples of many. One of the greatest challenges in assembling and using nanostructures and nano-materials is the necessity to control their size distribution and spatial arrangement on which their functionality ultimately depends.

The instrumentarium of surface science and in particular the invention of scanning probe techniques over twenty years ago, enables us now to probe the nanoscale properties and obtain real-space images of structures with atomic resolution. Surfaces play an increasingly important role as we progress from macroscopic materials to nanostructures: firstly, the relative number of surface atoms greatly increases, and secondly, we can use specific surface structures as template to tailor the formation of nanostructures.

In my presentation I will discuss several projects, which use surface science experiments to advance nanotechnology. The first, and major part will concentrate on the formation of Manganese-wires on the technically relevant Si(100) surface. The combination of manganese (with its high magnetic moment) and Si is one of the major challenges in building spintronic device structures based on Si-technology. The role of the Si-surface as a template for the spatial organization of Mn adatoms, the bonding between Mn and Si, and the progression to the formation of Silicide crystallites will be illustrated. The connection between the structural and electronic aspects and the potential of magnetic ordering is then discussed and forms the link between the atomistic view of surface structure and resultant property. The second part of my talk will focus on strategies to tailor nanostructures made from small organic molecules for future applications in organic solar cells. These strategies are developed from a fundamental understanding of the interaction between fullerenes and different surfaces.

 

*Please stop in early to enjoy some refreshments

 

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