Papers by Author: Xue Min Cui

Abstract: Making use of the amphoteric characteristic of zinc oxide and the weak acidity of hydrolyzed ammonium heptamolybdate, we synthesized high-purity zinc molybdate through chemical reactions. At optimum reaction temperature of 70°C, 1 hour of reaction time and reuse of mother liquor, the molybdenum yield exceed 98%. This process has no wastewater discharge, and the products can be easily filtered. The productivity is significantly increased.

Abstract: This paper studied the dielectric performances and microstructure of the Ba-Ti-B-Si-O glass-ceramics fabricated with different methods. The experimental results showed that the pre-calcined method was an effective way to decrease the sintering temperature in glass-ceramic fabricating process, and the dielectric properties of the LTCC materials were εr ≈10, tanδ ≤ 2×10-3 (@1MHz). This study provided a composite method to fabricate LTCC for different applications that was composed of pre-calcined powders and molten powders with different ratios; Moreover, the dielectric constant and sintering performance of composite LTCC were adjustable by changing the ratio of pre-calcined powders and molten powders.

Abstract: A series of ferrroelectric-ferromagnetic composites were synthesized from BaTiO3 and NiFe2O4 ferrite by conventional solid-state route. XRD studies indicated that the composites comprised of only two phases, BaTiO3 phase with perovskite structure and NiFe2O4 phase with spinel structure. Frequency dependence of permittivity and permeability were also measured. Experimental results showed that the dielectric constant and initial permeability of these composites could be tunable by varying the composition of composites. Thus, these composites can be used for multilayer chips EMI filters.

Abstract: As a good binder for aqueous Al2O3 suspensions tape-casting process, a commercial styrene-acrylic latex binder had been investigated. This paper studied on the rheological behaviors of the suspensions and drying process of aqueous slurries with latex binder system, and the research results indicated the rheological behaviors was affected by pH value, solid loading and dispersant (PAA-NH4) additives; and the drying speed of slurries was most decided by drying temperature and slurry coating thickness.

Abstract: This paper presents the shrinkage behavior, phase transformation and interfacial character of the hexagonal ferrite/silver electrode composite. The shrinkage analysis shows apparent sintering mismatch between hexagonal ferrite ceramic and silver electrode material and improvement of the co-fired characteristics was obtained by adding appropriate amount of sintering additive. Scanning electron microscopy observations indicate that silver grains distribute uniformly in the composite. Drawn from the back-scattered (BS) electron image, no silver dispersed into the ferrite grains and there’re no obvious chemical reactions between Co2Z hexagonal ferrite and silver, which can be confirmed by X-ray diffraction spectrum. Silver induction exerts remarkable effect on the electronic properties of the composite and could increase the dielectric constant and dielectric loss to a certain extent.

Abstract: A new method, which allowed lamination at room temperature without any additional adhesive, was described in this paper. A low Tg styrene-acrylic latex binder was used to forming the green tape via a water-based slurry. The green tapes could adhere to each other at room temperature under low or slight pressure. The density and deformation of laminated green parts depended significantly on lamination pressure, but the density of green parts did not increase after the lamination pressure exceeded a specific value of 4MPa. The interface between the tapes had been investigated in the green and sintered state by SEM. The experimental results showed that the microstructure of interface and density of lamination ceramics was a function of fraction of binder, plasticizer, and laminated pressure.