Effect of Ca substitution on the microwave properties and the inhibition of Ag diffusion in Ba1-xCaxMoO4 ceramics. Issue 10 (July 2020)

• Record Type: Journal Article
• Authors: Zhu, Haikui; Dong, Ye; Gu, Huidong; Bian, Wenjie; Zhang, Qitu
• Is Part Of: Ceramics international. Volume 46:Issue 10(2020)Part B
• Page Start: 16119
• Page End: 16125
• Publication Date: 2020-07
• Subjects: Ba1-xCaxMoO4 -- Sintering -- Cofiring -- Dielectric properties -- Ag diffusion inhibition; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.03.164
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Ba1-x Cax MoO4 (0 ≤ x ≤ 0.20) ceramics were prepared from powders to form solid solutions by a solid-state reaction sintering process. The influence of the Ca 2+ content on the microstructure, sintering, densification, microwave dielectric properties and chemical stability of BaMoO4 -based ceramics with Ag metal was discussed in detail. The sintering temperatures of the Ba1- x Ca x MoO4 ceramics were effectively reduced to less than 950 °C by the formation of the solid solutions. Structural analysis indicates that the Ba1-x Cax MoO4 ceramics belong to the class of tetragonal scheelites. The crystal grain size begins to decrease and become more regular as x increases from 0 to 0.12. However, as x continues to increase, a liquid phase begins to appear, and the grain boundaries are no longer clear. The ε r value increases from approximately 8.6 to 9.8 as x increases from 0 to 0.2. The Ba0.92 Ca0.08 MoO4 sample possesses the best microwave dielectric performance, namely an ε r = 9.3 and the maximum Q × f value of 33593 GHz. The addition of 15 wt% TiO2 or 10 wt% CaTiO3 can effectively change the τ f values of the Ba1-x Cax MoO4 ceramics to approximately 0. The Ba1-x Cax MoO4 ceramic samples can coexist with silver during the LTCC cofiring process.