Six‐principal‐component high‐entropy IVB–VB diborides: Low‐temperature synthesis, microwave absorption, and mechanisms

Abstract Owing to their outstanding performances significantly superior to that of the low‐ and medium‐entropy counterparts, high‐entropy diborides attracted extensive attention. Nevertheless, the rising configuration entropy of high‐entropy diborides rendered not only the better performances but also the greater formation difficulty due to the strengthened sluggish‐diffusion effect. Herein, high‐entropy (Hf 0.167 Zr 0.167 Ti 0.167 Ta 0.167 Nb 0.167 V 0.167 )B 2 , as the first reported six‐principal‐component high‐entropy IVB–VB transition‐metal diborides, was successfully synthesized by a microwave and molten‐salt co‐assisted thermal‐reduction method, under the temperature conditions (1400°C/20 min) remarkably milder than that required by the conventional method for synthesizing high‐entropy diborides. More importantly, the as‐synthesized high‐entropy diboride powders exhibited high composition uniformity, single‐crystalline nature and hexagon‐platelet‐like morphology. Furthermore, the high microwave absorption performance of high‐entropy (Hf 0.167 Zr 0.167 Ti 0.167 Ta 0.167 Nb 0.167 V 0.167 )B 2 was demonstrated to be favorable for enhancing its synthesis and self‐assembly by producing a unique micro‐zone hot‐spot effect. This research was predicted to promote the development of synthetic technique and dramatically expand the membership of high‐entropy materials.