Optimized sintering properties and temperature stability of MgZrTa2O8 ceramics with CuO addition for microwave application

• Published in: Journal of materials science. Materials in electronics Vol. 28; no. 24; pp. 18437 - 18441
• Main Authors: Xia, Wang-Suo, Zhang, Lan-Yang, Wang, Ying, Zhang, Jun-Ting, Feng, Rong-Rong, Shi, Li-Wei
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2017; Springer Nature B.V
• Subjects: Additives; Bulk density; Ceramics; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Crystal structure; Dielectric properties; Global positioning systems; GPS; Grain growth; Grain size; Materials Science; Optical and Electronic Materials; Permittivity; Resonant frequencies; Scanning electron microscopy; Sintering; Wolframite
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-017-7790-9

Microwave dielectric ceramics CuO–modified MgZrTa 2 O 8 were synthesized by the conventional solid-state reaction method. The effects of CuO additives on the sintering characteristics and microwave dielectric properties have been investigated. With CuO addition, the sintering temperature of MgZrTa 2 O 8 ceramics can be effectively lowered from 1475 to 1375 °C without decreasing its dielectric properties obviously and the temperature coefficient of the resonant frequency of MgZrTa 2 O 8 ceramics have been optimized to near-zero. The crystalline phase exhibited a wolframite crystal structure and no second phase was detected at low addition levels. The grain growth of CuO–modified MgZrTa 2 O 8 ceramics was accelerated due to liquid phase effect. The relative dielectric constants (ε r ) were correlated with apparent density and were not significantly different for all levels of CuO concentration. The quality factors (Q × ƒ) and temperature coefficient of resonant frequency (τ ƒ ), which were strongly dependent on the CuO concentration, were analyzed by the grain size and the dielectric constant respectively. A best Q × ƒ value of 116400 GHz and τ ƒ value of −6.19 ppm/℃ were obtained for specimen with 0.05 wt% CuO addition at 1375 °C.