Papers by Keyword: CO₂Z

Abstract: The Co2Z ferrites noise suppression sheet was prepared by tape casting. Its microstructural characterization was performed by electron microscopy and noise suppression effect was measured by a microstrip line method. Results indicate that as the sinter temperature increases, the imaginary permeability increases leading to the enhancement of the suppression capability, and the thickness of noise suppression sheets also contribute to the noise suppression capability.

Abstract: Magnetic and dielectric properties of conventional ceramics processed Ba₃Co₂Fe₂₄O₄₁ hexaferrite were investigated for microwave antenna miniaturization. Iron deficiency and optimizations of technology conditions have been used to control the high frequency properties of Co₂Z materials. The properties of the materials were characterized by SEM, XRD, Vector Network Analyzer, and so on. The experimental results showed that Z-phase was the main phase with traces of Y-phases for all the tested samples and the resonance frequencies were above 2GHz. 3BaO·2CoO·10.4Fe₂O₃ samples sintered at 1050°C had a loss tanδ_μ of 0.07 with the permeability of 7.28 at 1GHz and the miniaturization factor n reached a value up to 10 under 2GHz. It was found that Z-type hexaferrites with iron deficiency and low sintering temperatures met the demands of low-loss tanδ_μ for microwave antenna applications.

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.