Journal Article

High-entropy ceramics: Present status, challenges, and a look forward

Miao, Lei, Zhang, Guojun, Xing, Yan, Dai, Fu-zhi, Qi, Xiwei, Wang, Hailong, Wang, Yiguang, Xiang, Huimin, Wang, Hongjie, Zhou, Yanchun, Zhao, Biao, Li, Jianqiang, Su, Lei, Yao, Lei

2021

Overview

High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Although in the infant stage, the emerging of this new family of materials has brought new opportunities for material design and property tailoring. Distinct from metals, the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering. Aside from strengthening, hardening, and low thermal conductivity that have already been found in high-entropy alloys, new properties like colossal dielectric constant, super ionic conductivity, severe anisotropic thermal expansion coefficient, strong electromagnetic wave absorption, etc., have been discovered in HECs. As a response to the rapid development in this nascent field, this article gives a comprehensive review on the structure features, theoretical methods for stability and property prediction, processing routes, novel properties, and prospective applications of HECs. The challenges on processing, characterization, and property predictions are also emphasized. Finally, future directions for new material exploration, novel processing, fundamental understanding, in-depth characterization, and database assessments are given.

• Publisher: Tsinghua University Press,Springer,Science and Technology on Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials & Processing Technology,Beijing 100076,China%New Energy Technology Engineering Laboratory of Jiangsu Province,Nanjing University of Posts and Telecommunications,Nanjing 210023,China%State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi 'an 710049,China%Guangxi Key Laboratory of Information Materials,Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Material,School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China%Institute of Functional Material,College of Material Science and Engineering,Donghua University,Shanghai 201620,China%Institute of Advanced Structure Technology,Beijing Institute of Technology,Beijing 100081,China%College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China%College of Material Science and Engineering,Shenzhen University,Shenzhen 518060,China%School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China%Henan Key Laboratory of Aeronautical Materials and Application Technology,School of Material Science and Engineering,Zhengzhou University of Aeronautics,Zhengzhou 450046,China%National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,CAS Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China
• Subject: Alloys / Ceramic materials / Ceramics / Characterization and Evaluation of Materials / Chemistry and Materials Science / Composites / Crystal structure / Crystals / Dielectric strength / Electric waves / Electromagnetic radiation / Electromagnetic waves / Electromagnetism / Electronic structure / Entropy / Glass / High entropy alloys / Inorganic compounds / Ion currents / Materials Science / Nanotechnology / Natural Materials / Review / Solid solutions / Structural Materials / Structure / Thermal conductivity / Thermal expansion / Thermal properties