Shumin Duan, Zhenjun Qing, An Liu, Haiyan Li, Yan Xue
{"title":"Structure, bond features, and microwave dielectric properties of Li2(Mg1−xCax)2(MoO4)3 ceramics for ULTCC application","authors":"Shumin Duan, Zhenjun Qing, An Liu, Haiyan Li, Yan Xue","doi":"10.1111/jace.20074","DOIUrl":null,"url":null,"abstract":"<p>Ultra-low temperature sintered ceramics, Li<sub>2</sub>(Mg<sub>1−</sub><i><sub>x</sub></i>Ca<sub>x</sub>)<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> (<i>x</i> = 0.025–0.100), were synthesized using the solid-phase method. XRD analysis revealed that adding Ca<sup>2+</sup> increased the second-phase CaMoO<sub>4</sub> content. Particularly, Li<sub>2</sub>(Mg<sub>0.975</sub>Ca<sub>0.025</sub>)<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> ceramics exhibited excellent properties: <i>ε<sub>r</sub></i> = 9.31, <i>Q × f</i> = 55,400 GHz, and <i>τ<sub>f</sub></i> = −38.9 ppm/°C. Incorporating Ca<sup>2+</sup> significantly improved the performance of ceramics. The microwave dielectric properties of Li<sub>2</sub>(Mg<sub>0.9</sub>Ca<sub>0.1</sub>)<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> ceramics sintered at 650°C showed enhancements: <i>ε<sub>r</sub></i> of 9.55, <i>Q × f</i> of 63,500 GHz, and <i>τ<sub>f</sub></i> of −10.8 ppm/°C. The rise in <i>ε<sub>r</sub></i> can be attributed to polarizability, while a higher packing fraction led to a larger <i>Q × f</i> value, and the reduced distortion of the [Li/Mg/CaO<sub>6</sub>] octahedra enhanced the <i>τ<sub>f</sub></i> value. Moreover, the increased of CaMoO<sub>4</sub> also positively influenced the ceramic's properties. Furthermore, in accordance with the principles of complex chemical bonding, the elevation of ionicity, lattice energy, and bond energy of the Mo–O bond contributed to the enhancement of <i>ε<sub>r</sub></i>, <i>Q × f</i>, and <i>τ<sub>f</sub></i>, respectively. Raman spectroscopy showed a positive correlation between dielectric loss and full width at half maximum of the Raman peak. Good chemical compatibility between silver and Li<sub>2</sub>(Mg<sub>0.9</sub>Ca<sub>0.1</sub>)<sub>2</sub>(MoO<sub>4</sub>)<sub>3</sub> ceramic was demonstrated through our co-firing experiment.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"107 12","pages":"8281-8290"},"PeriodicalIF":3.5000,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the American Ceramic Society","FirstCategoryId":"88","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/jace.20074","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Ultra-low temperature sintered ceramics, Li2(Mg1−xCax)2(MoO4)3 (x = 0.025–0.100), were synthesized using the solid-phase method. XRD analysis revealed that adding Ca2+ increased the second-phase CaMoO4 content. Particularly, Li2(Mg0.975Ca0.025)2(MoO4)3 ceramics exhibited excellent properties: εr = 9.31, Q × f = 55,400 GHz, and τf = −38.9 ppm/°C. Incorporating Ca2+ significantly improved the performance of ceramics. The microwave dielectric properties of Li2(Mg0.9Ca0.1)2(MoO4)3 ceramics sintered at 650°C showed enhancements: εr of 9.55, Q × f of 63,500 GHz, and τf of −10.8 ppm/°C. The rise in εr can be attributed to polarizability, while a higher packing fraction led to a larger Q × f value, and the reduced distortion of the [Li/Mg/CaO6] octahedra enhanced the τf value. Moreover, the increased of CaMoO4 also positively influenced the ceramic's properties. Furthermore, in accordance with the principles of complex chemical bonding, the elevation of ionicity, lattice energy, and bond energy of the Mo–O bond contributed to the enhancement of εr, Q × f, and τf, respectively. Raman spectroscopy showed a positive correlation between dielectric loss and full width at half maximum of the Raman peak. Good chemical compatibility between silver and Li2(Mg0.9Ca0.1)2(MoO4)3 ceramic was demonstrated through our co-firing experiment.
期刊介绍：
The Journal of the American Ceramic Society contains records of original research that provide insight into or describe the science of ceramic and glass materials and composites based on ceramics and glasses. These papers include reports on discovery, characterization, and analysis of new inorganic, non-metallic materials; synthesis methods; phase relationships; processing approaches; microstructure-property relationships; and functionalities. Of great interest are works that support understanding founded on fundamental principles using experimental, theoretical, or computational methods or combinations of those approaches. All the published papers must be of enduring value and relevant to the science of ceramics and glasses or composites based on those materials.
Papers on fundamental ceramic and glass science are welcome including those in the following areas:
Enabling materials for grand challenges[...]
Materials design, selection, synthesis and processing methods[...]
Characterization of compositions, structures, defects, and properties along with new methods [...]
Mechanisms, Theory, Modeling, and Simulation[...]
JACerS accepts submissions of full-length Articles reporting original research, in-depth Feature Articles, Reviews of the state-of-the-art with compelling analysis, and Rapid Communications which are short papers with sufficient novelty or impact to justify swift publication.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
