Order-to-disorder transition due to entropy in layered and 2D carbides

• 成果类型: Article
• 署名作者: Wyatt, Brian C.; Yang, Yinan; Michalowski, Pawel P.; Parker, Tetiana; Morency, Yamilee; Urban, Francesca; Kadagishvili, Givi; Tanwar, Manushree; Muhoza, Sixbert P.; Nemani, Srinivasa Kartik; Bedford, Annabelle; Fang, Hui; Hood, Zachary D.; Jang, Junwoo; Kamath, Krutarth; Wright, Bethany G.; Disko, Rebecca; Thakur, Anupma; Han, Sanguk; Ghosh, Neil; Xu, Xianfan; Fakhraai, Zahra; Gogotsi, Yury; Vojvodic, Aleksandra; Jiang, De-en; Anasori, Babak
• 署名单位: Purdue University System; Purdue University; Vanderbilt University; Drexel University; Drexel University; University of Pennsylvania; University of Pennsylvania; United States Department of Energy (DOE); Argonne National Laboratory; Purdue University System; Purdue University; Purdue University in Indianapolis; University of Alabama System; University of Alabama Birmingham
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adv4415
• 发表日期: 2025-09-04
• 页码: 1054-1058
• 关键词: PHASE-STABILITY; MAX PHASES; xps; spectroscopy; mxenes; films

摘要

In compositionally complex materials, there is controversy on the effect of enthalpy versus entropy on the structure and short-range ordering in so-called high-entropy materials. To help address this controversy, we synthesized and probed 40 M4AlC3 layered carbide phases containing two to nine metals and found that short-range ordering from enthalpy was present until the entropy increased enough to achieve complete disordering of the transition metals in their atomic planes. We transformed all of these layered carbide phases into two-dimensional (2D) sheets and showed the effects of the order versus disorder on their surface properties and electronic behavior. This study suggests the key effect that the competition between enthalpy and entropy has on short-range order in multicompositional materials.