Na2CaTi2Ge3O12: An anti-reductive garnet ceramic with high quality factor and chemical compatibility with Cu/Ag electrodes for low temperature co-fired application

作者：Mei, Hongrong; Zhang, Liangbin; Rao, Zhenggang; Shu, Longlong; Gong, Weiping; Li, Chunchun^*

来源：Journal of Alloys and Compounds, 2022, 926: 166960.

DOI：10.1016/j.jallcom.2022.166960

• Microwave dielectric ceramics
• Garnet structure
• IR spectrum
• LTCC
• Anti-reductive

Microwave dielectric ceramics with excellent properties and low sintering temperatures are pursued saving energy and cofiring with metal electrodes (especially Ag, Cu). Herein, a low-firing Na2CaTi2Ge3O12 garnet was fabricated via a simple solid-state method. XRD, SEM, Raman spectrum, and dielectric characterization were used to reveal the influence of sintering temperature on crystal structure and dielectric properties. A single-phase Na2CaTi2Ge3O12 ceramic densified at 960 degrees C has the optimized dielectric properties with epsilon(r) = 15.3 +/- 0.2, Qxf = 55,900 +/- 2000 GHz, and tau(f) = -15.7 +/- 0.5 ppm/degrees C. The infrared (IR) spectrum was applied to estimate the intrinsic contribution of lattice vibration to microwave dielectric properties. The anti-reductive feature of Na2CaTi2Ge3O12 ceramic was evaluated via sintering at a reducing atmosphere while cofiring with Cu electrodes. The good chemical compatibility with Ag and Cu electrodes manifests the potential prospect of Na2CaTi2Ge3O12 ceramic in the low-temperature co-fired ceramic (LTCC) application.

• 单位
  惠州学院; 桂林理工大学; 南昌大学