Binfeng Zhao,Hongye Wang,Xinwei Xu,Naichao Chen,Jin Cheng,Xiaoyu Li,Hong Wang
The development of fifth-generation (5G)/sixth-generation (6G) mobile system highlights the importance of low-temperature co-fired ceramic (LTCC) technology. However, most medium- ε r ceramics with high quality factors are unsuitable for LTCC technology due to high sintering temperatures. Herein, a series of low-temperature-sintered ZnNb 2 O 6 - x wt.%CaV 2 O 6 ceramics, denoted as ZNO- x wt.%CVO( x =5,7,9,11), characterized by medium permittivity and high quality factors, were prepared by the solid-state reaction method. CaV 2 O 6 exists as a liquid phase during the sintering process. Moreover, liquid-phase sintering is confirmed to be the predominant mechanism for low-temperature densification of ceramics, with evidence from microstructure and activation energy. Ion substitution in the main crystalline phases, induced by ZnNb 2 O 6 –CaV 2 O 6 reaction during the sintering process, causes intrinsic impacts on microwave dielectric properties. Detailed structural analysis allows a comprehensive investigation into the extrinsic and intrinsic effects of CaV 2 O 6 on microwave dielectric properties, including quality factor Q × f , dielectric constant ε r , and temperature coefficient of resonant frequency τ f . Among all compositions, the ZNO-7 wt.% CVO ceramic sintered at 870°C exhibits great properties of Q × f = 57349 GHz, ε r = 21.63, τ f = −70.39 ppm/°C, as well as good chemical compatibility with silver (Ag). Given these advantages, the ZNO-7 wt.%CVO ceramic is a highly promising candidate for medium- ε r LTCC materials in 5G/6G applications.
Yuxiang Shen,Huan Liu,Raz Muhammad,Yang Yao,Xueqing Yu,Alexander Korotkevich,Minmin Mao,Lei Cao,Bing Liu,Haishen Ren,Huixing Lin,Matjaz Spreitzer,Mikhail P. Kuz'min,Ruzhong Zuo,Kaixin Song
In this study, 21.9 mol% MgO - 20.3 mol% Al 2 O 3 - 54.6 mol% SiO 2 + 1.6 mol% MnO 2 + 1.6 mol% ZnO and 23.1 mol% MgO - 20.9 mol% Al 2 O 3 - 55.0 mol% SiO 2 + 1.0 mol%GeO 2 were prepared by low-temperature co-firing method. The effects of nucleating agents and sintering temperature on the crystallization behavior, microstructure and microwave dielectric properties of MASMZ and MASG glass-ceramics were investigated. It was found that both glass-ceramics were able to precipitate stable α-cordierite crystalline phases at relatively low temperatures. Crystallization kinetics analysis showed that MASMZ glass-ceramics crystallized more easily than MASG glass-ceramics. MASMZ glass-ceramics exhibited optimal dielectric properties at 925 °C: ε r = 4.74, tan δ = 8.1 × 10 −4 , τ f = -14 ppm/°C. MASG glass ceramics achieved optimal dielectric properties at 950 °C: ε r = 4.46, tan δ = 1.11 × 10 −3 , τ f = -27 ppm/°C. Especially, the excellent chemical stability and compatibility of MASMZ and MASG glass-ceramics with silver at high temperatures were verified, indicating the potential of MASMZ and MASG glass ceramics as LTCC substrate materials.
危险品化学品经营许可证（带存储）