Single Crystal Growth by Solid State Reaction Synthesis: Informatics Driven Microstructural Analysis and Design

非技术描述：本研究探索了一类新型陶瓷的合成、结构和性能，即由金属和非金属元素组成的化合物。陶瓷单晶材料，其原子排列在整个散装样品是相同的，是可取的，因为其独特的性质。不幸的是，它们通常很难制造，需要专门的设备和非常高的温度。这个项目探索了一种新的固态方法来生长单晶陶瓷，从两种不同的陶瓷成分的混合物开始。潜在的存在是发现陶瓷晶体具有新的和有趣的性质，为下一代结构和电子应用。此外，可以利用相反的过程，即从单一材料转变为两种不同的材料来制造复合材料，这种复合材料是不同陶瓷或金属和陶瓷的微观混合物。这些混合物的规模和连通性可以定制，以改变整体物理性质。学生们正在接受包括实验和计算材料科学在内的先进技术的培训。他们通常会在高科技行业或政府/工业实验室找到工作。相关的外展活动旨在鼓励K-12学生从事科学和工程方面的职业，特别强调代表性不足的群体。这些努力包括创建双语教育模块，以及参与以下项目：1)面向高中学生和教师的材料营，2)面向中学女生的CHOICES（绘制工程和科学职业的视野和机会），以及3)面向经济和学业上处于不利地位和/或有风险的8至12年级学生的STAR（准备好了的学生）。技术细节：熵稳定氧化物是复杂的陶瓷，只有在一定的临界温度以上才稳定。迄今为止，这类材料很少受到研究界的关注。最近观察到一种新的转变，即固态合成诱导大块单晶生长，从两相多晶前驱体开始。相反，当退火温度低于临界温度时，这些材料的共析样转变产生新的两相形态。该项目结合了实验和基于信息学的建模方法，以寻求对转换机制的基本理解。特别是，本研究旨在确定材料的参数，这些参数与初始微观结构一起，定义了最终结构的形态和织构演变。研究生和本科生正在接受最先进的高温材料合成和表征技术的培训，以及成核和生长过程的建模。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: This research explores the synthesis, structure, and properties of a new class of ceramics, i.e. compounds composed of metallic and non-metallic elements. Ceramic single crystal materials, where the atomic arrangement is the same throughout the bulk sample, are desirable because of their unique properties. Unfortunately, they are usually difficult to fabricate, requiring specialized equipment and very high temperatures. This project explores a novel solid-state method for growing a single crystal ceramic, starting from a mixture of two different ceramic compositions. The potential exists for the discovery of ceramic crystals with new and interesting properties for next generation structural and electronic applications. Furthermore, the reverse process, i.e., changing from a single material to two distinct materials can be exploited to create composite materials that are microscopic mixtures of either different ceramics, or a metal and a ceramic. The scale and interconnectivity of these mixtures can be tailored to modify the overall physical properties. Students are undergoing training in advanced techniques encompassing both experimental and computational materials science. They will typically find employment in high tech industries or government/industrial laboratories. Associated outreach activities are directed towards encouraging K-12 students to pursue careers in science and engineering, with a particular emphasis on underrepresented groups. These efforts include the creation of bilingual educational modules, as well as participation in programs such as: 1) Materials Camps for high school students and teachers, 2) CHOICES (Charting Horizons and Opportunities In Careers in Engineering and Science), which is aimed at middle school girls, and 3) STAR (Students That Are Ready), which targets economically and academically disadvantaged and/or at-risk 8th to 12th grade students. TECHNICAL DETAILS: Entropy-stabilized oxides are complex ceramics that are stable only above a certain critical temperature. To date, this material class has received little prior attention from the research community. Recently a new type of transformation was observed whereby bulk single crystal growth was induced by solid state synthesis, starting with a two-phase, polycrystalline precursor. Conversely, the eutectoid-like transformation of these materials when annealed below the critical temperature yields novel two-phase morphologies. The project combines experiment and an informatics-based modelling approach to seek a fundamental understanding of the transformation mechanisms. In particular, the research aims to identify the materials' parameters that together with the initial microstructure, define the morphological and textural evolution of the resultant structure. Graduate students and undergraduates are being trained in state-of-the art high temperature materials synthesis and characterization techniques, as well as modelling of nucleation and growth processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.