Preparation and dielectric properties of SiO2/silicate-1 ceramics

For exploring the using of silicate-1 zeolite in dielectric ceramic, SiO₂@silicate-1 ceramics were fabricated by combining oxidation-bonding, sol–gel directional infiltration and sintering methods. The resulting samples were analyzed by X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, digital hardness tester and microwave dielectric measurement system. It can be found that silicate-1 particles are well bond by silica sol. And the pores of perform are partially filled with silica. The sintering temperature has great effect on microstructure and properties of SiO₂@silicate-1 ceramics. When the ceramic is sintered at 400 and 600 °C, it keeps the MFI-type structure and almost has the same low-dielectric-constant (5.71 and 5.62, respectively). When the ceramic is sintered at 800 and 1000 °C, its MFI-type structure is broken down and its dielectric constant is 7.38 and 6.75, respectively.