About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Local Ordering in Materials and Its Impacts on Mechanical Behaviors, Radiation Damage, and Corrosion
|
Presentation Title |
Short Range Order in Disordered Spinel and the Impact on Cation Vacancy Transport |
Author(s) |
Peter Hatton, Blas Pedro Uberuaga |
On-Site Speaker (Planned) |
Peter Hatton |
Abstract Scope |
Spinels are important complex oxides for use in radiation damage environments and resulting from the corrosion of steels. It is known that, in these environments, normal spinels exist with some concentration of antisite cation pairs known as inversion. We use atomistic modeling to show that even in highly disordered states characterized by high levels of inversion, spinel still shows some short-range order that manifests itself in antisite chains. The propensity to form these antisite chains is confirmed through Monte Carlo simulations in FeCr2O4, NiCr2O4 and MgAl2O4. We consider the effect of antisite chains on the diffusivity of cation vacancies and find the effect strongly depends on the spinel chemistry. At the extremes, chains significantly increase or drastically decrease vacancy transport depending on spinel chemistry. These dramatically different effects are explained by the assessment of the thermodynamic stability of the antisite chains and contrasting attractive/repulsive interactions of vacancies with the chains. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, |