New Quaternary MAX Phase Thin Films: Understanding the Thermally Induced Microstructural Evolutions and Reaction Mechanisms in Nanostructured Multilayers via Experimental Combinatorial Study

新型四元 MAX 相薄膜：通过实验组合研究了解纳米结构多层膜中的热致微观结构演化和反应机制

• 批准号: 464878149
• 负责人: Dr.-Ing. Chongchong Tang, Ph.D.
• 金额: --
• 依托单位: Institut für Angewandte Materialien - Angewandte Werkstoffphysik (IAM-AWP)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/464878149?language=en
• 关键词: New; Quaternary; MAX; Phase; Thin

MAX phase materials (Mn+1AXn, M = transition metal, A = A group element, X = carbon or nitrogen, n =1, 2, 3) are atomically layered compounds that possess unique properties combining attributes of both metals and ceramics. Multi-elemental alloying of individual atomic layers is a powerful tool to synthesize novel quaternary MAX phases and offers manifold opportunities to widely tune their properties through tailoring their local chemistry and structural complexity. Recently, apart from random solid solution structures, new chemically ordered quaternary (M′M″)n+1AXn structures on M layers have been discovered, including out-of-plane ordering (referred to as o-MAX) and in-plane ordering (referred to as i-MAX). However, the synthesis of such bulk quaternary MAX phases in single-phase structure remains a great challenge. Thin-film synthesis of quaternary MAX phase materials is an emerging research field in materials science, and, chemically ordered quaternary MAX phase thin films have not been reported yet. In this proposal, we aim to synthesize single-phase and, potentially, basal-plane textured quaternary (M′M″)n+1AXn thin film materials in three quaternary model systems (Cr-M″-Al-C with M″: V, Ti, Zr). This will be achieved by transformation of nanoscale elemental multilayers with pre-defined nanostructured architectures (“thin film precursors”) through appropriate treatment processes, utilizing an experimental combinatorial approach for the thin film precursor design and synthesis. The research work will target at first the synthesis of quaternary random solid solution MAX phases, and will then address the synthesis of the two complex ordered structures. The scientific objectives of this proposal are: 1) to understand the microstructural evolutions and their underlying reaction mechanisms during thermal processing of the nanostructured multilayers towards the formation of different quaternary MAX phase thin films, and, 2) to explore the composition–microstructure–properties relationship of the quaternary MAX phase thin films. The thermal processing of the thin film precursors will cover annealing experiments at various heating rates and kinetics (i.e. very low as well as fast heating rates), including selected experiments with a novel thin film calorimeter. The scientific work will be based on intensive thin film characterization methods with atomic-scale resolution. Thus, the proposed research will contribute to developing suitable thin film precursor architectures and thermal treatment processes for the synthesis of phase-pure quaternary MAX phase thin films. The scientific outcome will lead to an understanding of the role of local chemistry (composition and chemical ordering) and microstructure on the properties of such new MAX phase thin film materials.

MAX 相材料（Mn+1AXn，M = 过渡金属，A = A 族元素，X = 碳或氮，n =1,2,3）是原子层状化合物，具有结合金属和陶瓷属性的独特性能。单个原子层的多元素合金化是合成新型四元 MAX 相的强大工具，并提供了多种机会通过定制其局部化学和结构复杂性来广泛调整其性能。近年来，除了随机固溶体结构外，还发现了M层上新的化学有序四元(M′M″)n+1AXn结构，包括面外有序(简称o-MAX)和面内有序(简称i-MAX)。然而，在单相结构中合成这种大块四元 MAX 相仍然是一个巨大的挑战。四元MAX相材料的薄膜合成是材料科学中的一个新兴研究领域，目前化学有序四元MAX相薄膜尚未见报道。在本提案中，我们的目标是在三个四元模型系统（Cr-M”-Al-C 和 M”：V、Ti、Zr）中合成单相和潜在的基面织构四元 (M′M″)n+1AXn 薄膜材料。 这将通过适当的处理工艺，利用薄膜前体设计和合成的实验组合方法，对具有预先定义的纳米结构结构（“薄膜前体”）的纳米级元素多层进行转化来实现。研究工作首先针对四元随机固溶体MAX相的合成，然后将解决两种复杂有序结构的合成。该提案的科学目标是：1）了解纳米结构多层膜在形成不同四元 MAX 相薄膜的热处理过程中的微观结构演变及其潜在反应机制，2）探索四元 MAX 相薄膜的成分-微观结构-性能关系。薄膜前驱体的热处理将涵盖各种加热速率和动力学（即非常低和快速的加热速率）下的退火实验，包括使用新型薄膜量热计进行的选定实验。这项科学工作将基于具有原子级分辨率的密集薄膜表征方法。因此，所提出的研究将有助于开发合适的薄膜前驱体结构和热处理工艺，用于合成纯相四元 MAX 相薄膜。科学成果将有助于了解局部化学（成分和化学排序）和微观结构对此类新型 MAX 相薄膜材料性能的作用。