Sintering Mechanism and Microwave Dielectric Characteristics of Low-Fired Mg₄Nb₂O₉ Ceramics for LTCC Applications

Abstract

The low-fired Mg₄Nb₂O₉ ceramics were fabricated by a solid-state reaction method for developing LTCC applications. By addition LiF as sintering aid, the sintering temperatures of Mg₄Nb₂O₉ ceramics were successfully lowered to 950 °C due to the substitution of F^- for O²⁻. The oxygen bond strength could be weakened by the substitution of F⁻ for O²⁻, which reduced the intrinsic sintering temperature and facilitated the diffusion process. The microwave dielectric properties of ɛ_r = 12.3, Q × f = 62450 GHz, τ_f = −57.5 ppm/°C were obtained for Mg₄Nb₂O₉-4 wt.% LiF ceramics, which suitable for LTCC applications.

Keywords:

• Mg₄Nb₂O₉
• sintering mechanism
• dielectric characteristics
• LTCC

Additional information

Funding

This work is supported by Anhui Provincial Natural Science Research Project of High Education Institutions in China (Grant nos. KJ2019ZD10), Anhui University of Science and Technology Introduced Talent Research Startup Fund.