Nanoscale Switching Phenomena and Size Effects in Ferroelectric Thin Films Studied by Scanning Force Microscopy

North Carolina State University, Raleigh NC

Investigators

Abstract

This project address fundamental materials science issues associated with ferroelectric thin films and their potential application as nonvolatile memories. The approach is to use, and further de-velop, scanning force microscopy (SFM) to investigate structure/property relationships on the micro- and nanoscale levels. Salient areas for investigation include: reconstruction of the 3-D domain structure of ferroelectric films and capacitors at the sub-grain level; characterization of capacitor domain structures before and after pulse switching to evaluate the role of pulse charac-teristics and microstructural features such as film composition, thickness, grain size and orienta-tion, and defects, on switching and domain stability. It is expected that the combination of fast pulse switching with domain imaging will allow testing of the applicability of quantitative switching models. The capability to characterize domain structure, domain motion and switching at the nanoscale will allow further insight and understanding of scaling and intrinsic variability issues. The proposed research links expertise in nanoscale characterization of ferroelectric mate-rials by SFM (Gruverman) with strength in synthesis of functional ferroelectric films at NCSU (Kingon). The experimental research in combination with recently refined phenomenological theory for ferroelectric films will be undertaken in collaboration with S. Streiffer of Argonne Na-tional Laboratory. %%% The project addresses fundamental research issues in areas of ceramics and electronic ma-terials science having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The project provides clas-sic materials science research for graduate student training, linking processing, local (nanoscale) characterization, device properties, and theory. Additionally, demonstrator experiments, based on SPM research will be developed and used to attract future students, including under-represented minorities, into materials science. The research program provides excellent opportunities for hands-on experience in the use of sophisticated scientific equipment. The broad resources, and collaborative aspects, provide special opportunities for education and training of graduate and undergraduate students involved in interdisciplinary forefront research. ***