高熵硅铝化物:一类新型的高熵陶瓷材料（英文）

High-entropy alumino-silicides: a novel class of high-entropy ceramics

高熵陶瓷材料因具有巨大的组分空间、独特的微观结构以及可调控的性能而引起国内外研究者的广泛关注.目前,高熵陶瓷材料的研究主要集中在具有多主元阳离子结构的高熵陶瓷材料领域.然而,关于具有多主元阴阳离子结构的高熵陶瓷材料的研究报道较少.本文首次报道了一类新型的具有多主元阴阳离子结构的高熵陶瓷材料,即高熵硅铝化物(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2.首先基于第一性原理计算从化学反应热力学和晶格尺寸差异两个方面分析了高熵硅铝化物形成的可能性,然后以过渡金属粉体以及硅粉和铝粉为原料,采用固相反应技术在1573 K下成功地制备出等摩尔比的高熵硅铝化物.研究结果表明:所制备的高熵硅铝化物具有单一金属硅铝化物的六方晶系晶体结构,同时,所有组成元素的分布具有高度均匀性.该研究不仅丰富了高熵陶瓷材料的种类,而且为开拓具有多主元阴阳离子结构的高熵陶瓷材料提供了参考.

High-entropy ceramics(HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides(Mo0.25Nb0.25Ta0.25V0.25)(Al0.5Si0.5)2(HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity.This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.