Improved microwave dielectric properties of CaMgSi2O6 ceramics through CuO doping

• Main Authors: Lai, Yuanming, Su, Hua, Wang, Gang, Tang, Xiaoli, Liang, Xiaofeng, Huang, Xin, Li, Yuanxun, Zhang, Huaiwu, Ye, Chen, Wang, Renshaw Xiao
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; CaMgSi2O6 Ceramic; Microwave Dielectric Property
• Online Access: https://hdl.handle.net/10356/144723
• Institution: Nanyang Technological University

High-performance dielectric materials for microwave communication requires low dielectric constants (εr < 10), high quality factor (Qf) and near-zero temperature coefficient of resonance frequency (τf). However, CaMgSi2O6 ceramics typically exhibit low Qf and largely negative τf, despite its low εr. In this study, nominal composition CaMg1-xCuxSi2O6 (0 ≤ x ≤ 0.16) ceramics were synthesized via a solid-state reaction. Enhanced microwave dielectric properties were achieved in the x = 0.04 ceramic sintered at 1250 °C with εr = 7.41, Qf = 160 100 GHz (two times better than the previously reported values), and τf = −42 ppm/°C. Benefited from the optimal CuO doping, this enhancement in microwave dielectric property was realized by the contribution of order structure and the densification. Excess CuO doping, which can lead to a phase transition (from C2/c to P21/c), could degenerate the microwave dielectric properties of the CaMgSi2O6 ceramics. Considering the excellent microwave dielectric properties, the CuO-doped CaMgSi2O6 ceramic is a promising candidate material for microwave communication applications.