Entropy regulation in Mg4Nb2O9-based microwave dielectric ceramics to implement promising excellent temperature stability and mechanical properties

被引：0

作者：

Huang, Chun-e ^{[1
,2
,3
]}

Zhang, Jing ^{[3
]}

Gu, Jian ^{[1
,2
]}

Li, Quan ^{[1
,2
]}

Yang, Jian ^{[1
,2
]}

机构：

[1] College of Materials Science and Engineering, Nanjing Tech University, Nanjing,211816, China

[2] Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing,211816, China

[3] Wuxi Vocational Institute of Arts and Technology, Yixing,214206, China

来源：

Journal of the European Ceramic Society | 2025年 / 45卷 / 16期

关键词：

Antimony compounds - Ceramic materials - Dielectric materials - Entropy - Grain refinement - Magnesium compounds - Manganese oxide - Niobium compounds - Solid state reactions - Tantalum compounds - Tungsten compounds - Vanadium compounds;

D O I：

10.1016/j.jeurceramsoc.2025.117699

中图分类号：

学科分类号：

摘要：

Entropy-regulated Mg4Nb2O9-based microwave dielectric ceramics (MWDC), Mg4Nb2O9 (MNO), Mg4(Nb1/3Sb1/3Ta1/3)2O9 (M3NO), Mg4(Nb1/4Sb1/4Ta1/4V1/4)2O9 (M4NO), and Mg4(Nb1/5Sb1/5Ta1/5V1/5W1/6)2O9 (M5NO) were synthesized by the solid-state reaction method. By modulating Nb-O bond valence and [NbO6] octahedral distortion, medium-entropy M3NO ceramics sintered at 1400 ℃ exhibited a near-zero τf (-14.47 ± 9.87 ppm/℃), which was successfully improved compared with MNO ceramics (-57.96 ± 8.32 ppm/℃). Furthermore, significant enhancements in bending strength (σf) and fracture toughness (KIC) were achieved due to grain refinement and dislocation strengthening mechanisms. Specifically, M3NO ceramics demonstrated σf of 182.82 ± 16.91 MPa and KIC of 2.86 ± 0.21 MPa·m^1/2. These values represent a 305 % increase in σf and an 87 % enhancement in KIC compared to MNO ceramics, which exhibited values of 45.12 ± 5.34 MPa and 1.53 ± 0.44 MPa·m^1/2. This work opens up a new pathway for improving temperature stability and mechanical properties of MWDC by entropy regulation strategy. © 2025

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