Simulation Studies of Entropically-Stabilized Quasicrystals and of Nanophase Materials (Materials Research)

准晶材料具有五重对称性，与周期性平动顺序不相容。最初提出了两种准晶体结构模型：准周期晶体或“彭罗斯平铺”模型和二十面体玻璃模型。斯特兰德伯格博士的研究，连同其他一些人的研究，提出了第三种可能性——熵稳定或“随机平铺”模型。在这个项目中，她将使用计算机模拟技术来研究：(1)三维随机平铺模型的性质。结果将允许与实验进行比较，以区分建议的结构模型；(2)随机平铺模型的晶体生长和界面粗糙度。纳米晶体是纳米大小的晶体的压缩物。由于晶界密度大，它们具有新颖的性能。这些材料对晶粒生长的异常稳定性将使用一个简单的拓扑模型进行研究。互动活动包括阿贡和费米实验室的女学生与女科学家配对的导师项目；物理学女学生定期聚会，讨论科学领域女性感兴趣的问题；博士论文研究指导；教授本科物理导论和研究生固体物理。该项目进一步推进了VPW计划的目标，即(1)为女性提供在工程和NSF支持的科学学科中发展职业的机会；(2)通过为在工业、政府和学术机构工作的女性科学家和工程师提供更大的知名度，鼓励女性在科学和工程领域追求职业。通过鼓励妇女参与科学，这是对国家未来科学活力的宝贵投资。

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.