@article{Chen2023, 
author = {Deqin Chen and Na Yan and Xuefeng Cao and Fengrong Li and Laijun Liu and Qinghua Shen and Huanfu Zhou and Chunchun Li},
title = {Entropy regulation in LaNbO4-based fergusonite to implement high-temperature phase transition and promising dielectric properties},
year = {2023},
journal = {Journal of Advanced Ceramics},
volume = {12},
number = {5},
pages = {1067-1080},
keywords = {high-entropy ceramics, microwave dielectric property, ion disorder, far-infrared},
url = {https://www.sciopen.com/article/10.26599/JAC.2023.9220739},
doi = {10.26599/JAC.2023.9220739},
abstract = {High-entropy effect is a novel design strategy to optimize properties and explore novel materials. In this work, (La1/5Nd1/5Sm1/5Ho1/5Y1/5)NbO4 (5RNO) high-entropy microwave dielectric ceramics were successfully prepared in the sintering temperature (S.T.) range of 1210–1290 ℃ via a solid-phase reaction route, and medium-entropy (La1/3Nd1/3Sm1/3)NbO4 and (La1/4Nd1/4Sm1/4Ho1/4)NbO4 (3RNO and 4RNO) ceramics were compared. The effects of the entropy (S) on crystal structure, phase transition, and dielectric performance were evaluated. The entropy increase yields a significant increase in a phase transition temperature (from monoclinic fergusonite to tetragonal scheelite structure). Optimal microwave dielectric properties were achieved in the high-entropy ceramics (5RNO) at the sintering temperature of 1270 ℃ for 4 h with a relative density of 98.2% and microwave dielectric properties of dielectric permittirity (εr) = 19.48, quality factor (Q×f) = 47,770 GHz, and resonant frequency temperature coefficient (τf) = –13.50 ppm/℃. This work opens an avenue for the exploration of novel microwave dielectric material and property optimization via entropy engineering.}
}