Order-to-disorder transition due to entropy in layered and 2D carbides
Brian C. Wyatt, Yinan Yang, Paweł Piotr Michałowski, Tetiana Parker, Yamilée Morency, Francesca Urban, Givi Kadagishvili, Manushree Tanwar, Sixbert P. Muhoza, Srinivasa Kartik Nemani, Annabelle Bedford, Hui Fang, Zachary D. Hood, Junwoo Jang, Krutarth Kamath, Bethany G. Wright, Rebecca Disko, Anupma Thakur, Sanguk Han, Neil Ghosh, Xianfan Xu, Zahra Fakhraai, Yury Gogotsi, Aleksandra Vojvodić, De‐en Jiang, Babak Anasori
Abstract
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 M 4 AlC 3 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.