Three‐phase borate solid solution with low sintering temperature, high‐quality factor, and low dielectric constant
Rui Peng, Yuanxun Li, Hua Su, Yongcheng Lu, Liang Shi, Guoliang Yu, Gang Wang, Gongwen Gan, Chengyong Yu
Abstract
Abstract The sintering and microwave dielectric properties of a ceramic material based on the mixing of Mg 3 B 2 O 6 and Zn 3 B 2 O 6 have been widely studied using first‐principles calculations and experimental solid‐state reactions. Characterization methods include the Network Analyzer, X‐ray, Raman diffraction, scanning electron microscopy, energy‐dispersive spectroscopy, and differential‐thermal and thermo‐mechanical analyzer. The increasing amount of Mg 2+ results in the appearance of Mg 2 B 2 O 5 and ZnO, and the mutual substitution (Mg 2+ and Zn 2+ ) phenomenon has emerged in Zn 3 B 2 O 6 and Mg 2 B 2 O 5 . The mechanisms have been explained with the help of DFT calculations. The bond parameters and electron distributions of the ZnO 4 tetrahedron and MgO 6 octahedron have been modified due to substitution. The sintering, substitution, and phase formation properties have been analyzed quantitatively through the energy parameters. The best dielectric properties were obtained for x = 0.20 sintered at 950°C, ε r = 6.47, Q × f = 89 600 GHz (15.2 GHz), τ f = −48.6 ppm/°C, relative density = 96.7%. The mixing of Zn 3 B 2 O 6 and Mg 3 B 2 O 6 ceramics is a feasible method to obtain a ceramic with low sintering temperature and excellent dielectric properties.