About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Progress in High Entropy Materials: Integrating Experiments, Computation, and Machine Learning
|
| Presentation Title |
Understanding Oxygen Vacancies Energetic in Mg-O Based High Entropy Oxides from DFT |
| Author(s) |
Oriyomi Opetubo, Ting Shen, Rajendra Bordia, Dilpuneet Aidhy |
| On-Site Speaker (Planned) |
Oriyomi Opetubo |
| Abstract Scope |
High entropy oxides (HEOs) have attracted wide interests of ceramics community due to multitude of alloying chemistries for functional properties. The random distribution of multiple cations causes diversity in the nearest neighbor environment (NN) around oxygen atoms, which influence energetics of oxygen vacancies, critical in oxide materials. In this work, using density functional theory (DFT) calculations, we investigate the energetics of oxygen vacancies in Mg(CoCuNiZn)O HEO. Our calculations show that oxygen vacancy formation energies decrease significantly in the presence of Cu, due to its lower charge transfer and it causes more lattice distortion due to its intrinsic Jahn-Teller effect than other cations. In addition, we perform nudged elastic band (NEB) calculations to understand oxygen vacancy migration barriers in difference NN environment, including local lattice distortion, which can enhance or trap oxygen diffusion. Understanding these concepts contribute to kinetics of oxygen vacancy migration and electrochemical applications. |
