Sintering Behavior and Microwave Dielectric Properties of MgO-2B 2 O 3 - Xwt %H 3 BO 3 - Ywt %BCB Ceramics

Abstract

The bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 series ceramics synthesized by solid-state reaction method were systematically studied in this paper. X-ray diffraction and microstructural analysis revealed that the as-prepared MgO-2B2O3 ceramics possessed a single-phase structure with rod-like morphology. Through the investigation of the effects of different dosages of H3BO3 and BCB on bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 ceramics, the optimum sintering temperature was obtained at an addition of 30wt%H3BO3 and 8wt%BCB and the sintering temperature was reduced to 825 oC. The addition of 40wt %H3BO3 and 4 wt%BCB increased the quality factor Q×f, permittivity εr and temperature coefficient of resonance frequency τf of MgO-2B2O3 to 44,306 GHz, 5.1 and -32 ppm/oC, respectively, meeting the criteria of low-temperature co-fired ceramics.

Mg3B2O6 microwave dielectric ceramics fabricated by combining cold sintering with post‐annealing process

“…Excess H 3 BO 3 was added to the MBO formula to compensate for the volatilization of B 2 O 3 , [15][16][17] Figure 2A-D shows the bulk and relative density of MBO ceramics prepared with different cold-sintering conditions. With the increase of glacial acetic acid content and cold-sintering temperature/pressure/time, the bulk and relative density of MBO ceramics is found to increase significantly.…”

B2O3‐modified geopolymer and its liquid‐phase sintered products for immobilization of strontium

“…The reasons for this can be described as liquid-phase sintering accelerating the atomic rearrangement during the phase transitions, leading to a compact microstructure of the loading substrate. 42,43 When treated at the temperature of 1000 • C, the product with the addition of 2.0 wt% B 2 O 3 possesses the best immobilization property of leaching rate of 1.29%. It can be noticed that the relationship between immobilized efficiency of simulated radioactive strontium and high temperature treatment temperature of the (Na, Sr)-GP with different B 2 O 3 doping contents is similar, the maximum leaching rate at 800 • C and the minimum leaching rate at 1000 • C.…”

Structure, far-infrared spectroscopy, microwave dielectric properties, and improved low-temperature sintering characteristics of tri-rutile Mg 0.5Ti 0.5TaO 4 ceramics

“…(ii) Dielectric properties of dense Mg 0.5 Ti 0.5 TaO 4 ceramics in the microwave region mainly rely on lattice vibration; however, there are no relevant studies on the intrinsic dielectric properties' investigation that hinders further understanding of its high-frequency dielectric characteristics. (iii) The sintering temperature of Mg 0.5 Ti 0.5 TaO 4 ceramics is as high as 1350 ℃; can it decrease the temperature while maintaining the excellent microwave dielectric properties [14]? Thus, to solve the above issues, Mg 0.5 Ti 0.5 TaO 4 ceramics were synthesized in this study, where the structural type is investigated by the Rietveld refinement analysis, far-infrared reflectance spectra, and transmission electron microscopy (TEM).…”