Low temperature sinterable vanadate microwave dielectric ceramic Ca0.5M4V3O12 and preparation method thereof

Abstract

The invention discloses a low temperature sinterable vanadate microwave dielectric ceramic Ca0.5M4V3O12 and a preparation method thereof. The material composition of the low temperature sinterable vanadate microwave dielectric ceramic is Ca0.5M4V3O12, wherein the M is one of Zn and Mg. The preparation method comprises the following steps of (1) weighing original powders of CaCO3, MO and VO3 with the purity above 99.9% according to the chemical formula of the Ca0.5M4V3O12, wherein the M is one of Zn and Mg; (2) carrying out wet ball-milling mixing for 12 hours, taking distilled water as a solvent, drying and pre-burning for 6 hours at the temperature of 750 DEG C; and (3) adding an adhesion agent, granulating, carrying out compression moulding and finally sintering for 4 hours at the temperature of 800-900 DEG C, wherein a polyvinyl alcohol solution with the mass concentration of 5% is adopted as the adhesion agent and the dose of the adhesion agent accounts for 3% of the total dose of the powder. The ceramic disclosed by the invention has the advantages that the sintering is good at the temperature of 850-900 DEG C, the dielectric constant is up to 10-11, the quality factor is up to 57000-83000GHz and the temperature coefficient of resonance frequency is small, and therefore, the ceramic has great application value in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a microwave dielectric ceramic material for microwave components used at microwave frequencies, such as a dielectric substrate, a resonator, and a filter, and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in circuits in the microwave frequency band (mainly UHF and SHF bands) and perform one or more functions. They are widely used as resonators, filters, and dielectric substrates in modern communications. Components such as chips and dielectric waveguide circuits are the key basic materials of modern communication technology. They have been used in portable mobile phones, car phones, cordless phones, TV satellite receivers and military radars. They are used in modern communication tools. It is playing an increasingly important role in the process of miniaturization and integration. ...

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Problems solved by technology

[0010] In the process of exploring and developing new low-firing microwave dielectric ceramic materials, material systems such as Li-based compounds, Bi-based compounds, tungstate compounds, and tellurate-based compounds with inherently low sintering temperatures have received extensive attention and research. A large number of exploratory studies have focused on Li-based binary or ternary compounds, and developed such as Li 2 TiO 3 , Li 3 NbO 4 , Li 2 MoO 4 and Li 2 MTi 3 o 8 (M=Mg or Zn) series of microwave dielectric ceramics with good performance, etc., but the microwave dielectric ceramic system that can be fired at low temperature is still relatively limited, which limits the development of low temperature co-firing technology and microwave multilayer devices to a large extent.

Recently, researchers at home and abroad have studied some vanadates such as Mg 3 (VO 4 ) 2 , Mg 2 V 2 o 7 and A 2 V 2 o 7 (A = Ba, Sr or Ca) ceramic microwave dielectric properties were reported, we [see literature Liang Fang, Congxue Su, Huanfu Zhou, Zhenhai Wei, Hui Zhang, Novel Low-Firing Microwave Dielectric Ceramic LiCa 3 MgV 3 o 12 with Low Dielectric Loss, Journal of the American Ceramic Society, 2013, 96(3):688-690] the pair composition is LiCa 3 MgV 3 o 12 The sintering characteristics and microwave dielectric properties of the cubic garnet structure lithium-containing vanadate ceramics were studied, and it was found that the sintering temperature of this type of ceramics was 900 ° C and can be co-fired with silver electrodes at low temperature, its dielectric constant is 10.5, and the Qf value reaches 74 700GHZ, but the temperature coefficient of the resonance frequency τ ? Too large (-47 ppm / ℃) and unable to meet the practical requirements

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