Preparation and design of barium feldspar-based microwave dielectric ceramics from graphite tailings

• Published in: Journal of the European Ceramic Society 2025-06, Vol.45 (6), p.117179, Article 117179
• Main Authors: Zhu, Shuai, Wang, Xin, Li, Yuhui, Lu, Xiaochi, Cao, Liang, Yu, Lei, Wang, Zhefei
• Format: Article
• Language: English
• Subjects: Barium feldspar; Graphite tailings; Ionic substitution; Microwave dielectric ceramic
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2024.117179

Novel barium feldspar-based microwave dielectric ceramics derived from graphite tailings (BAS-GT) were prepared via the solid-state reaction method. The effects of Sr2 + substitution on the phase composition, microstructure and microwave dielectric properties of sintered ceramics were investigated. Results demonstrated that the barium feldspar solid solution co-existed with Ca2Al2SiO7 when excess Sr2+ was introduced. The Sr2+ substitution effectively improved the densification and microwave dielectric properties of the BAS-GT ceramics, especially the quality factor (Q×f) and temperature coefficient of resonant frequency (τf), attributed to the optimised phase composition and good sintering behaviour. A component standard for utilising graphite tailings in microwave dielectric ceramics was established. The 10 mol% Sr2+ substituted BAS-GT ceramic samples sintered at 1150 °C exhibited optimised microwave dielectric properties, with εᵣ = 7.13, Q×f = 28,452 GHz, and τf = –27.12 ppm/°C, indicating significant potential of these ceramics for applications in 5 G wireless communication technology.