Stabilizing high-entropy MAX phases by incorporating tin
Lei Cao, Xinghua Zhu, Shuai Fu, Detian Wan, Yiwang Bao, Yanchun Zhou, Man Jiang, Longsheng Chu, Qingguo Feng, Chunfeng Hu
Abstract
High-entropy nanolaminated materials, referred to as MAX phases, have exceptional potential in various fields, including physics, mechanics, and energy storage, owing to their diverse compositions and outstanding properties. However, synthesizing stable high-entropy phases presents significant challenges because of the considerable differences in the physical and chemical properties of complex elements. In this study, we added low-melting-point metal tin (Sn) as an additive to facilitate the formation of solid solutions. The cohesion energy and formation enthalpy of the Sn-containing system are negative, which maintains the thermodynamic stability of the system, and the incorporation of Sn decreases the mixing enthalpy of the target high-entropy MAX phase and inhibits the formation of competing phases. The addition of Sn increases the lattice parameter and improves the structural stability by increasing the lattice distortion of octahedral M<sub>6</sub>X and prism M<sub>6</sub>A, which facilitates the successful synthesis of single-phase high-entropy MAX bulk materials. In addition, the high-entropy MAX phases with added Sn retain good mechanical and physical properties. This study provides a novel approach for the synthesis and application of high-entropy MAX phase materials, which has the potential to contribute to advancements in multiple technological fields.