Niobate microwave dielectric ceramic LiMNb3O9 and preparation method thereof

Abstract

The invention discloses a niobate microwave dielectric ceramic LiMNb3O9 and a preparation method thereof. The niobate microwave dielectric ceramic material is constituted by LiMNb3O9, wherein M is one of Zn, Mg and Ni. The preparation method comprises the steps of: (1) weighing and mixing the raw powder of Li2CO3, MO and Nb2O5 with the purity over 99.9% according to the LiMNb3O9 chemical formula, wherein the M is one of Zn, Mg and Ni; (2) mixing the raw materials in the step (1) by wet-type ball milling for 12 hours with distilled water as the solvent, and an obtained mixture is dried and then pre-burned at 1000 DEG C for 6 hours; and (3) adding a binder into the powder prepared in the step (2) for pelleting, molding by pressing and finally sintering the molded product at 1050-1100 DEG C for 4 hours, wherein a polyvinyl alcohol solution with the mass concentration being 5% is employed as the binder and the the binder accounts for 3% of the total powder. The ceramic prepared according to the invention is well sintered at 1050-1100 DEG C, has a dielectric constant being 37-41, a quality factor Qf as high as 55000-82000GHz, a small temperature coefficient of resonance frequency and has great value in industry application.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a dielectric ceramic material for microwave components such as resonators and filters used at microwave frequencies 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. [0003] Dielectric ceramics used in th...

AI Technical Summary

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, Zn) and other series of microwave dielectric ceramics with good performance, etc. However, the low-fire microwave dielectric ceramic system is still relatively limited, which largely limits the development of low-temperature co-firing technology and microwave multilayer devices.

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