High-entropy (HE) ultra-high temperature ceramics have the chance to pave the way for future applications propelling technology advantages in the fields of energy conversion and extreme environmental shielding. Among others, HE diborides stand out owing to their intrinsic anisotropic layered structure and ability to withstand ultra-high temperatures. Herein, we employed in-situ high-resolution synchrotron diffraction over a plethora of multicomponent compositions, with four to seven transition metals, with the intent of understanding the thermal lattice expansion following different composition or synthesis process. As a result, we were able to control the average thermal expansion (TE) from 1.3 x 10−6 to 6.9 x 10−6 K−1 dependingon the combination of metals, with a variation of in-plane to out-of-plane TE ratio ranging from 1.5 to 2.8.


Materials Science and Engineering

Publication Status

Open Access


National Science Foundation, Grant CMMI-1902069

Keywords and Phrases

Anisotropic Thermal Expansion; Borides; High-Entropy Ceramics; Spark Plasma Sintering; Synchrotron Diffraction; Ultra-High Temperature Ceramics

International Standard Serial Number (ISSN)

2631-7990; 2631-8644

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2023 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Mar 2023