Quasicrystalline materials are intriguing because of their fivefold symmetry which is incompatible with periodic translational order. Two models of quasicrystal structure were originally proposed: the quasiperiodic crystal or "Penrose tiling" model and the icosahedral glass model. Dr. Strandburg's research, along with that of a number of others, suggested a third possibility - the entropically stabilized or "random tiling" model. In this project she will use computer simulation techniques to study: (1) properties of the random tiling model in three dimensions. Results will allow comparisons with experiment, to distinguish between the suggested structural models; and (2) crystal growth and interface roughness of the random tiling model. Nanocrystals are compactions of nanometer-sized crystallites. They have novel properties due to their large density of grain boundaries. The anomalous stability of these materials against grain growth will be investigated using a simple topological model. Interactive activities include a mentorship program pairing female students with women scientists at Argonne and Fermilab; regular gatherings of female physics students for discussion of issues of interest to women in science; Ph.D. thesis research supervision; and teaching introductory undergraduate physics and graduate solid state physics. This project furthers VPW program objectives which are (1) to provide opportunities for women to advance their careers in engineering and in the disciplines of science supported by NSF and (2) to encourage women to pursue careers in science and engineering by providing greater visibility for women scientists and engineers employed in industry, government, and academic institutions. By encouraging the participation of women in science, it is a valuable investment in the Nation's future scientific vitality.
