NSF-Europe: Nanoscale Ferroelectric and Piezoelectric Phenomena in Ultrathin Oxide Heterostructures

University Of Maryland, College Park, College Park MD

Investigators

Abstract

This is a collaborative project between researchers at the University of Maryland and at Rheinisch-Westfalische Technische Hochschule (RWTH) Aachen, Germany. The project aims to create ferroelectric nanostructures and characterize polarization dynamics in them. Earlier work has shown that ferroelectric polarization is is well-behaved down to lateral sizes of 70 nm3. When the ferroelectric volume shrinks to a few nanometers, there arises a competition between thermal excitation (kT) and dipolar interactions that lead to the existence of a polar state. Re-search activities are focused on two areas: exploration of size scaling effects in these thin films; and comprehensive understanding of nanoscale dynamical phenomena that impact the functional-ity of these materials. A major challenge is to fabricate and integrate functional oxides with other materials at nanometer dimensions, and to determine and understand their properties. This pro-ject expects progress through a combination of advanced materials processing and fabrication approaches, incorporation of state-of-the-art nanolithography tools (such as focused ion beam milling and e- beam lithography) to create nanostructures and the use of a variety of nanoscale resolution probes to study and understand dynamical physical phenomena at the nanoscale. Ac-tivities at Aachen will emphasize advanced device processing, while scanned probe characteriza-tion will be addressed at Maryland. In addition both institutions will participate in computational and theoretical modeling. %%% The project addresses fundamental research issues associated with electronic materials having technological relevance. An important feature of the project is the strong emphasis on education, with emphasis on integration of research and education, and an international collaboration pro-viding both scientific and educational benefits. An important component of this interaction will be exchange of students for extended periods of time. During summers, a student-exchange pro-gram will allow graduate students from Maryland to conduct research in Aachen, and vice versa. Additionally, senior members will present lectures at the partner's location to further foster inter-actions. This NSF project is co-funded by the Office of Multidisciplinary Activities, the Division of Materials Research (Electronic Materials, and Ceramics Programs), and the International Of-fice (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135). This project is being carried out in collaboration with Rheinisch-Westfalische Technische Hochschule (RWTH) Aachen, Germany. ***