About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Local Ordering in Materials and Its Impacts on Mechanical Behaviors, Radiation Damage, and Corrosion
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Presentation Title |
Long- and Short-range Ordering versus Disordering in Compositionally Complex Fluorite-based Oxides |
Author(s) |
Jian Luo |
On-Site Speaker (Planned) |
Jian Luo |
Abstract Scope |
This talk will review our recent work on investigating long- and short-range orders and order-disorder transitions (ODTs) in compositionally complex fluorite-based oxides (CCFBOs). In 2018, we first reported the YSZ-like high-entropy fluorite oxides [JECS 2018]. Subsequently, we fabricated a series of medium- and high-entropy (ordered) pyrochlore oxides and showed that size disorder controls reduced thermal conductivity [Scripta 2020]. We further proposed to extend “high-entropy ceramics (HECs)” to "compositionally complex ceramics (CCCs)" [JECS 2020; JMS 2020] to include non-equimolar compositions and short- and long-range ordering that reduce configurational entropies but offer additional dimensions to tailor and improve properties. We discovered composition-induced [Acta 2021] and redox-induced [Scripta 2022] pyrochlore-fluorite ODTs in 10- and 11-compomnent CCFBOs. We showed the short-range weberite ordering cause ultralow thermal conductivity [Acta 2022]. We discovered ultrahigh-entropy weberite and fergusonite phases and a pyrochlore–weberite transition in 21-component CCFBOs [JAC 2022]. On-going (unpublished) results will also be discussed. |
Proceedings Inclusion? |
Planned: |