Structure-Composition-Property Relationships in Complex Intermetallic Phases: Experimental and Theoretical Studies

本项目旨在通过实验和理论相结合的方法，系统地寻找具有潜在物理和化学性质的新金属间化合物。由于成分的细微变化会对金属间化合物的结构和物理性质产生巨大的影响，电子结构的理论计算将对这些相的完整和系统的研究起到重要的作用。新的多元化合物的合成和详细表征将涉及(I)正电碱、碱土或稀土金属；(Ii)过渡金属；以及(Iii)第13族元素(铝、镓、铟)，或镁或锰。13族元素之所以被选中，是因为它们在元素周期表中的位置在金属和非金属之间。这些元素的组合有望创造出美丽的复杂结构，包括相互连接和相互穿透的原子簇，这将使人们能够彻底研究成分、结构、性能和化学键之间的关系。%可能用作热电材料的材料，或作为预计对环境友好的坚固高温导体的材料将被合成和表征。该项目将让化学、物理和材料科学的学生通过爱荷华州立大学和艾姆斯实验室工作，促进这些行业感兴趣的材料科学领域的发展。学生将学习高温化学、分析、衍射和电子结构理论的方法。这项关于固体结构和结合的基本研究成果正在被纳入爱荷华州立大学开设的课程。

This project aims to use both experiment and theory to systematically search for new intermetallic compounds with potentially interesting physical and chemical properties. Since subtle changes of composition can lead to drastic effects on structural and physical properties in intermetallics, theoretical calculations of electronic structure will play a significant role in a complete and systematic study of these phases. The synthesis and detailed characterization of new multinary compounds will involve (i) an electropositive alkali, alkaline earth, or rare earth metal; (ii) a transition metal; and (iii) a group 13 element (aluminum, gallium, indium), or magnesium or manganese. The group 13 elements are selected because their position in the periodic table of elements is at the border between metals and nonmetals. These combinations of elements are anticipated to create beautifully complex structures involving interconnected and interpenetrating clusters of atoms that will allow a thorough investigation of the relationships among composition, structure, properties, and chemical bonding.%%%Materials with possible applications as thermoelectrics, or as strong, high temperature conductors that are anticipated to be environmentally benign will be synthesized and characterized. The project will involve students of chemistry, physics and materials science working through Iowa State University and the Ames Laboratory to advance these areas of materials science of significant interest to industry. Students will learn methods in high temperature chemistry, analysis, diffraction and electronic structure theory. Fundamental results from this research regarding the structure and bonding of solids are being incorporated into courses being offered at Iowa State University.***