Method for stabilizing Zn2TiO4 spinel microwave dielectric ceramics and improving quality factor of Zn2TiO4 spinel microwave dielectric ceramics

Abstract

The invention discloses a method for stabilizing Zn2TiO4 spinel microwave dielectric ceramics and improving a quality factor of the Zn2TiO4 spinel microwave dielectric ceramics. The chemical composition formula of a microwave dielectric ceramic material is (1-x)Zn2TiO4-xLi4 / 3Ti5 / 3O4, wherein x is not smaller than 0.1 and not greater than 0.4. The method comprises the following steps of firstly, weighing and dispensing Li2CO3, ZnO and TiO2 raw materials with the purity of over 99 percent according to the composition of the (1-x)Zn2TiO4-xLi4 / 3Ti5 / 3O4; secondly, performing wet ball milling and mixing on the raw materials in the first step for 4 hours, and preburning in the atmosphere of 900DEG C for 8 hours after drying, wherein a ball milling medium is ethanol; thirdly, adding a binding agent in powder obtained in the second step and granulating, performing compression molding, and finally, sintering the mixture in the atmosphere of 1,078-1,200DEG C for 4 hours, wherein the binding agent is polyvinyl alcohol solution with the mass concentration of 5 percent, and the dose accounts for 7 percent of the total mass of the powder. According to the method disclosed by the invention, a Zn2TiO4 spinel structure can be remarkably stabilized; the quality factor Q*f value of the Zn2TiO4 spinel structure can be improved from 2120 to 69900GHz.

Description

technical field [0001] The invention belongs to the field of electronic ceramics and its manufacture, and relates to dielectric ceramic materials for microwave components such as dielectric substrates, antennas and resonators used at microwave frequencies and a preparation method thereof. [0002] Background technique [0003] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in circuits in microwave frequency bands (mainly UHF and SHF bands) and perform one or more functions. It is a new type of functional ceramics that has developed rapidly in the past 30 years. It can be used as an insulating substrate material in microwave circuits, and is also a key material for manufacturing microwave dielectric filters and resonators. Microwave dielectric ceramics with high dielectric constant, low dielectric loss, and near-zero resonant frequency temperature coefficient can be used to manufacture microwave components such as dielectric antennas, f...

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Problems solved by technology

[0005]Zn2TiO4 is a spinel structure compound, the raw material cost and sintering temperature of this type of material are both is low, but its structure is extremely unstable, resulting in poor microwave dielectric properties of the material (εr=19.2, Q×f=2120 GHz, τf=-85 ppm / °C)

Replace Zn by a small amount of Mn2+, Co2+, Ni2+ or Cu2+ ions【 1, 2], can stabilize its structure, but the Q×f value of ceramics is still very low (≤16000 GHz)

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