Ultra‐low temperature sintering microwave dielectric ceramics based on Ag2O–MoO3 binary system

• Published in: Journal of the American Ceramic Society 2017-06, Vol.100 (6), p.2604-2611
• Main Authors: Zhang, Gao‐qun, Guo, Jing, Wang, Hong
• Format: Article
• Language: English
• Subjects: Aluminum; Binary systems; Ceramic powders; Ceramics; Densification; dielectric materials/properties; Dielectric properties; Low temperature; LTCC; Molybdenum trioxide; Operating temperature; Permittivity; Sintering; Sintering (powder metallurgy); Temperature
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.14760

The Ag2Mo2O7 and Ag6Mo10O33 ceramics for ultra‐low temperature co‐fired ceramic application were prepared by the solid‐state reaction route. The optimized densification temperatures of Ag2Mo2O7 and Ag6Mo10O33 are 460°C and 500°C, respectively. The phase structures and microstructures of these ceramics were systematically studied. The Ag2Mo2O7 ceramic sintered at 460°C/4 h exhibits excellent microwave dielectric properties with εr=13.3, Q×f=25 300 GHz and τf=−142 ppm/°C at 9.25 GHz. The Ag6Mo10O33 ceramic sintered at 500°C/4 h shows the microwave dielectric properties with εr=14.0, Q×f=8500 GHz and τf=−50 ppm/°C at 9.00 GHz. Moreover, when Ag2Mo2O7 samples are sintered at ultra‐low sintering temperatures of 420°C‐490°C, the Q×f values of them are all above 20 000 GHz. Besides, the Ag2Mo2O7 ceramic does not react with silver powder or aluminum powder. The variation of relative permittivity, resonant frequency, and Q×f values as a function of operating temperature has been also studied. All the results indicate that the Ag2Mo2O7 ceramic is a good candidate for ultra‐low temperature co‐fired microwave devices.