Papers by Author: Xian Li Huang

Abstract: A modified polyacrylamide precursor method is presented to synthesize BaSm2Ti4O12 microwave dielectric ceramics. Under an alkaline circumstance, all the cations together with the monomer and bridging agent were dispersed into a hydrous solution with the aid of chelating agent EDTA. This mixture was initiated at about 90°C, dried, calcined at 1000°C for 2hs and finally turned into well-crystallized and single-phased BaSm2Ti4O12 ceramic powder, which was modeled and sintered at 1250°C for 2hours into well-sintered ceramics. Differential thermal analysis, thermogravimetric analysis, X-ray powder diffraction and transmission electron microscope were used to characterize the process. Microwave dielectric properties measured by a resonating cavity method contain a dielectric constant (εr) about 77.0 and quality factor (Q×f) lager than 11000.

Abstract: BaTi4O9 - BaPr2Ti4O12 microwave dielectric ceramic composite powders were prepared by a polyacrylamide gel route using ethylenediaminetetraacetic acids (EDTA) as a chelating agent. This method provides a fast, cheap, reproducible and easy to scale-up way to prepare homogeneous mixed phases compounds. A light green, molecular-level, homogeneously mixed gel was prepared by the gelification of acrylamide. The precursors and derived oxide powders were characterized by thermal analysis (TG-DSC) and X-ray powder diffraction (XRD). Two phases and well-crystallized BaTi4O9 - BaPr2Ti4O12 composite powders were obtained at 1200 °C for 4 h.