Three‐phase borate solid solution with low sintering temperature, high‐quality factor, and low dielectric constant

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.

Efficient Preparation of BNNSs and Their Performance Study of Reinforced Porous Si3N4 Composites by Gel Casting

“…Figure a shows the XRD patterns of ZnB 2 O 4 precursors, reaction products, and BNNSs after purification at different reaction temperatures. As observed in Figure a, the XRD pattern of ZnB 2 O 4 precursors after reaction at 900 °C is basically consistent with the peaks of ZnB 2 O 4 , Zn 3 B 2 O 6 , and h-BN, indicating that the reaction is not complete. − There are still many ZnB 2 O 4 precursors not involved in the reaction, which remain in the products. After purification by pickling, the products still contain the diffraction peak of ZnB 2 O 4 .…”

Low dielectric loss ceramics in the Mg4Nb2O9-ZnAl2O4-TiO2 ternary system

“…Table S1 (supplementary materials) shows the lattice parameters of the MZT015 sintered at various temperatures. The lattice parameters of Mg4Nb2O9 and Mg5Nb4O15 decreased with increasing sintering temperature due to the increase in the ion substitution of Ti 4+ (ionic radius = 0.60 nm) for Nb 5+ (ionic radius = 0.61 nm) [20]. Figure 2 shows the relative densities of the samples sintered at various temperatures.…”

Low‐k dielectric materials derived from ZSM‐5 zeolite

“…5 Silicate raw materials are cheap and easy to obtain, so they have been widely studied. 13 In addition, phosphate [14][15][16][17][18][19] and borate [20][21][22][23] ceramics have also been studied because of their low permittivity. Most of the low-k microwave dielectric materials currently studied have a dielectric constant between 5 ∼ 10, 4,5,13 and only a few materials indicate a dielectric constant lower than 5.…”