|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Hume-Rothery Symposium on Connecting Macroscopic Materials Properties to Their Underlying Electronic Structure: The Role of Theory, Computation, and Experiment
||Construction and Application of Defect Phase Diagrams
||Joerg Neugebauer, Ali Zendegani, Tilmann Hickel
|On-Site Speaker (Planned)
Deviations from the ideal bulk stoichiometry of ordered intermetallic compounds are commonly realized by point defects, such as antisites or vacancies. Recent high-resolution electron microscopy experiments show, however, a second mechanism: A high concentration of extended defects such as stacking faults that can accommodate large amounts of alloying elements. To understand the formation and thermodynamics of such highly nonstoichiometric defects we have adapted and generalized the concept of defect phase diagrams. These diagrams show, in analogy to the well-established thermodynamic bulk phase diagrams, the thermodynamically most stable defect phase as function of state variables such as temperature, chemical potential, stresses etc. The power and performance of this concept are demonstrated using the example of nonstoichiometric stacking faults in the Fe-Nb Laves phase where these diagrams are shown to provide an accurate tool to correctly predict the rich set of experimentally observed defect structures [Acta Materialia 183, 362 (2020)].
||Modeling and Simulation, Phase Transformations,