The Role of Point Defects in the Structure and Properties of Perovskites for Functional Applications

非技术描述：钙钛矿家族中的陶瓷具有有用的性质，并且在包括电瓷、超导体、耐火材料、催化剂、磁阻器、自旋电子学和质子导体的应用中遇到。 晶体缺陷在所有工程陶瓷中非常常见，了解晶体缺陷影响结构和性能的方式对科学和工业都非常重要。 模型，帮助预测的结构，并通过扩展，性能是非常有用的理解和设计的材料与工程性能，而无需昂贵的试验和错误，但现有的理论模型是不足以描述这样的陶瓷。 他们对这个问题的双重方法涉及使用精心选择的代表性钙钛矿系统的实验组件，以及理论计算组件。 这种结合的方法可能导致更高质量的功能陶瓷，并且仅对3500亿美元的蜂窝电信行业的影响就可能包括更有效的滤波器，最终导致多媒体应用的更高数据速率，并最终减少所需的蜂窝天线杆的总数。 外联到更大的社区将发生通过杰森项目，家庭工程日，每年的“BSU日与立法者”，UIUC少数民族外联和保留计划，UIUC工程开放日，和“项目带路”中学教师。 此外，由项目参与者创建和维护的一个网站将成为教授固态化学以及材料科学和技术方面的有用工具;因此，资金将继续支持其多方面和非常成功的推广活动。有助于预测结构的模型，在理解和设计具有工程性质的材料时，这些性质是非常有用的，而无需昂贵的试验和错误，然而现有的理论模型不足以描述这种陶瓷。 另一方面，他们使用精心选择的代表性钙钛矿系统的实验方法克服了这些缺点，并且已经成功地证明了这一点。 在该项目中，通过先进的化学加工方法合成了几种复杂的陶瓷组合物，分析了所得的晶体结构，并测量了性能，以完成预测结构模型。 计算结构模型正在同时开发，以验证和补充经验推导的，增加了一个额外的维度的理解结构和相变的建模。 然后，预测模型可以用于寻找具有新的和有趣的特性的新钙钛矿。 该项目的教育影响是强大的和多种多样的。参与的学生将接受包括中子衍射和透射电子显微镜在内的尖端表征技术的培训，他们所获得的国际曝光将对他们未来的职业生涯具有形成性和极高的价值。

NON-TECHNICAL DESCRIPTION: Ceramics in the perovskite family have useful properties and are encountered in applications including electroceramics, superconductors, refractories, catalysts, magnetoresistors, spintronics, and proton conductors. Understanding the way crystal defects, which are very common in all engineering ceramics, affect structure and thereby properties is of great importance to both science and industry. Models which aid the prediction of structure and, by extension, properties are extremely useful in both the understanding and designing of materials with engineered properties without expensive trial and error, yet existing theoretical models are inadequate to describe such ceramics. Their dual approach to this problem involves both an experimental component, using a well-chosen representative perovskite system, plus a theoretical computational component. This combined approach may result in much higher quality functional ceramics, and the impact on the $350-billion cellular telecommunications industry alone could include more efficient filters leading eventually to higher data rates for multimedia applications and ultimately a reduction in the overall number of cellular masts required. Outreach to the greater community will occur via the Jason Project, Family Engineering Day, the annual "BSU Day with the Legislators", the UIUC Minority Outreach and Retention Program, UIUC Engineering Open House, and "Project Lead the Way" for secondary teachers. In addition, a web site created and maintained by project participants will become a useful tool for teaching aspects of solid-state chemistry as well as materials science and technology; therefore, funding continues to support their multi-faceted and highly successful outreach activities.TECHNICAL DETAILS: Models which aid the prediction of structure and, by extension, properties are extremely useful in both the understanding and designing of materials with engineered properties without expensive trial and error, yet existing theoretical models are inadequate to describe such ceramics. Their experimental approach using a well-chosen representative perovskite system, on the other hand, overcomes these shortcomings and has already been successfully demonstrated. In this project, several complex ceramic compositions are being synthesized via an advanced chemical processing method, the resulting crystal structures analyzed, and properties measured in order to complete a predictive structural model. Computational structural models are simultaneously being developed to verify and complement the empirically derived ones, adding an additional dimension of understanding to the modeling of structure and phase transitions. The predictive models could then be used to find new perovskites with new and interesting properties. The educational impact of the project is strong and varied. The international exposure gained by the students involved, who will be trained in cutting-edge characterization techniques including neutron diffraction and transmission electron microscopy, will be formative and extremely valuable for their future careers.