Advances in Powder and Ceramic Materials Science: High Entropy Ceramics I
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Materials Characterization Committee, TMS: Powder Materials Committee
Program Organizers: Bowen Li, Michigan Technological University; Dipankar Ghosh, Old Dominion University; Eugene Olevsky, San Diego State University; Kathy Lu, University of Alabama Birmingham; Faqin Dong, Southwest University of Science and Technology; Jinhong Li, China University of Geosciences; Ruigang Wang, Michigan State University; Alexander Dupuy, University of Connecticut
Monday 8:30 AM
March 20, 2023
Room: 30A
Location: SDCC
Session Chair: Alexander Dupuy, University of California Irvine; Bowen Li, Michigan Tech
8:30 AM Introductory Comments
8:50 AM Keynote
Microstructure Engineering Using Entropic Phase Transformations: Julie Schoenung1; 1University of California, Irvine
Significant advancements in ceramic science are required to address emerging societal challenges such as climate change and the need for better energy storage technologies. The necessary breakthroughs will require the reevaluation of existing ceramic design strategies. In this presentation, I will discuss how leveraging the complex chemistry in entropy stabilized oxides (ESOs) allows for unique phase transformations that can be tuned to precisely and reversibly control phase distribution, microstructure, properties, and behavior. I will discuss how chemistry, processing, and microstructure can be used to control the phase transformation and design the microstructure in ESOs. Then I will present examples of how the resulting phase heterogeneity can be used to tune mechanical and functional behavior, with a particular emphasis on applications relating to electronics and energy storage. These examples demonstrate that transformative results can be achieved through strategic use of complex ceramic chemistries and innovative materials processing methods.
9:20 AM Invited
Compositionally Complex Oxide Ceramics: Synthesis, Structure and Properties: Horst Hahn1; 1Karlsruhe Institute of Technology
Following the concept of metallic high entropy alloys, a first publication on a single phase oxide with 5 transition metal cations triggered an enormous increase of research efforts in the field of high entropy oxides (HEO). Meanwhile, many different systems with rocksalt, fluorite, perovskite, spinel, etc., structures have been prepared by a multitude of chemical, mechanical and physical synthesis techniques, in the form of powders, bulk structures and thin films. In addition to the different crystallographic structures and elements incorporated in HEO, the complexity becomes enormous if non-equiatomic compositions are considered. The enormous number of possible compositions has initiated recently efforts in high throughput synthesis and characterization. Electrochemical, catalytic, magnetic, and optical properties, some with potential for applications, have been studied for the different systems. An overview of the current status of the research on compositionally complex oxide powders and ceramics is presented.
9:40 AM Invited
Compositionally Complex Oxides: Synthesis, Characterization, Challenges, and Opportunities: Veerle Keppens1; 1University of Tennessee
High entropy oxides (HEOs), also referred to as multicomponent oxides or compositionally complex oxides (CCOs), have attracted attention due to the tunability of multiple cations on a single site. Since the introduction in 2015 of HEOs stabilized in the rocksalt phase, the high entropy oxide concept has been expanded to various structures, offering a path for the discovery of innovative compounds with unique structure-property relations. However, the intrinsic disorder and highly localized chemical environments of HEOs bring along new challenges. In order to shed light on the complexities associated with multi-cation oxides, we have initiated a systematic study of polycrystalline and single crystalline HEO samples across multiple crystal systems. This work expands the multi-component concept to new compositions and crystal systems and investigates properties of materials across multiple crystal systems, including spinel, perovskite, and Ruddlesden-Popper multi-component materials.
10:00 AM Break
10:20 AM
Design of High Entropy Ceramics with IGZO-based Compounds for Electroceramics Applications: Zaid Alejandro Luzanilla Meléndrez1; Alejandro Durán2; Francisco Brown1; Ofelia Hernández Negrete1; Javier Hernández Paredes1; Victor Emmanuel Alvarez Montano1; 1Universidad De Sonora; 2Universidad Nacional Autónoma de México
Indium Gallium Zinc Oxide (IGZO) is a ceramic material used in optoelectronic technology, having essential results such as high efficiency in energy consumption and better image quality in display devices. On their side, high entropy ceramics (HECs) are relevant in many present studies due to some novel and better physical properties behavior. In this work, we studied the design of HECs with IGZO-based compounds by the solid-state method. Several trivalent and divalent cations are substituted in the layered crystal structure of IGZO, and the equilibrium of phases is studied under different compositions and high temperatures. The classic quenching method is used cooling to room temperature. Phase equilibrium was monitored using X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM) to reveal microstructure and cation distribution with elemental mapping. In addition, the dielectric and optical properties will be obtained to analyze their possible applications.
10:40 AM Invited
Applying the High Entropy Concept in Single-atom Catalysts and Ceramic Battery Cathode Active Materials: Huolin Xin1; Rui Zhang1; Chunyang Wang1; Lili Han1; 1University of California - Irvine
The high configurational entropy concept has seen significant inroads in applications areas such as strengthening structural materials such as alloys and ceramics. However, the concept poses a grand challenge in realizing equimolar composition in many emerging materials systems as the thermodynamics of the low-temperature phase does not favor composition homogeneity. In this talk, I will specifically talk about how to overcome the aforementioned challenge and demonstrate that it is possible to use single-atom anchor sites as structural units to assemble concentration-complex single-atom catalyst materials with up to 12 different elements. I will also talk about how to utilize the “high entropy” concept correctly in ceramic battery electrode materials to enable breakthrough electrochemical performances.Han, L., Cheng, H., Liu, W. et al. A single-atom library for guided monometallic and concentration-complex multimetallic designs. Nat. Mater. 21, 681–688 (2022). https://doi.org/10.1038/s41563-022-01252-y
11:00 AM
Grain size Confinement of Secondary Phases in Entropy Stabilized Oxides: Alexander Dupuy1; Julie Schoenung1; 1University of California, Irvine
Entropy stabilized oxide (ESO) materials contain at least five oxide components, which form a single phase that is stabilized through entropy. A unique characteristic of ESOs is their reversible entropy-driven phase transformation, presenting an opportunity to produce oxide materials with controlled microstructures. In (CoCuMgNiZn)O, this transformation manifests as the formation of a Cu-rich tenorite secondary phase. We demonstrate experimentally that as-sintered grain size significantly influences the morphology of the secondary phase. Large grain sizes yield needle-shaped secondary phases within the grains. Smaller grain sizes confine the secondary phase, resulting in a transition in morphology. We also observe a region adjacent to the grain boundary that is depleted in secondary phase. This depletion region becomes more prevalent at smaller grain sizes, leading to the observed confinement effect. The confinement effect follows a simple geometric model, allowing for the secondary phase morphology in (CoCuMgNiZn)O to be predicted based on grain size.
11:20 AM
Electrical Behavior of Multi-phase Entropy-stabilized Oxides: Arturo Meza1; Alina Vizcaya1; Alexander Dupuy1; Julie Schoenung1; 1University of California Irvine
Entropy-stabilized oxides (ESO) consist of five or more oxide components that form a random solid solution structure after processing. ESOs have garnered significant attention due to their interesting functional properties and expanded compositional space. For example, (Cu,Co,Mg,Ni,Zn)O shows promise for fuel cell and batteries components. Here we explore the role of processing, microstructure, and secondary phases on the electrical behavior of bulk (Co,Cu,Mg,Ni,Zn)O. Samples were consolidated using conventional sintering and heat treated at a range of temperatures and times to control the phase state. Temperature dependent impedance spectroscopy was used to investigate the role of microstructure on the electrical conductivity and activation energy for electrical transport. Electron and atomic force microscopy techniques were used to characterize the microstructure and tie it to the electrical behavior. Results show that processing and microstructure significantly influence the electrical behavior in (Co,Cu,Mg,Ni,Zn)O. Mechanisms governing the contribution of microstructure to electrical behavior will be discussed.