Defektdesign von Keramiken über Stapelfehler-Grenzflächen

The quote "Crystals are like people: growth and defects are what make them interesting" is attributed to Sir Frederick Charles Frank, a British physicist renowned for his work on the theory of crystal growth and dislocations. Together with Thornton Read, Frank introduced the concept of the FrankRead source of dislocations, a specific type of imperfection in crystals. He emphasized that these defects play a significant role in the performance of real- life materials, which is why studying flaws is so important. Indeed, the development of materials with exceptional properties often depends on how precisely tailored defects can be introduced into their structures. These defects play a crucial role in various processes such as deformation and phase transitions, and they influence important material properties like electrical and thermal conductivity, hardness, and toughness. Particularly interesting are stacking faultsdisruptions in the orderly stacking of atomic layersespecially in ceramics with different atomic planes. However, the underlying atomic processes are not yet fully understood, posing challenges for applications such as protective coatings, structural components in high-temperature environments, and energy storage systems. Our goal is to develop a detailed understanding of how different types of defects, such as point and planar defects, interact in high-temperature ceramics. We are focusing on materials like transition-metal nitrides and diborides, which are known for their strength and stability under extreme conditions. By investigating how these defects affect the crystal structure and the material`s response to stress, we hope to develop new methods to enhance thermal stability, strength, and toughness. Ultimately, this knowledge will help us create guidelines for designing ceramic materials with outstanding properties. We will manufacture materials using a technique called physical vapor deposition, which allows us to introduce and control defects in a targeted manner. These materials will then be analyzed using advanced tools to study their behavior under different conditions. Additionally, we will use detailed computer simulations to model these processes at the atomic level and gain insights into how atomically-sharp interfaces influence the material`s response to temperature changes and stress. While defects (imperfections) are often seen as a disadvantage, our research aims to intentionally design them to improve material performance. Our project combines cutting- edge experimental techniques with advanced simulations, including innovative methods like molecular dynamics with machine learning. This approach will enable us to develop new methods for creating superior (ceramic) materials.