Microwave dielectric ceramic Li2Zn2W2O9 capable of being sintered at low temperature and preparation method thereof

Abstract

The invention discloses application of composite oxide Li2Zn2W2O9 as a microwave dielectric ceramic capable of being sintered at low temperature; and a preparation method of the dielectric ceramic comprises the following steps: (1) weighing for batching Li2CO3, ZnO and WO3 original powder with the purity of more than 99.9% according to the chemical formula Li2Zn2W2O9; (2) mixing the raw materials of the steps (1) by wet ball milling for 12 hours with a milling medium being distilled water, drying, then presintering at 650 DEG C in air atmosphere for 6 hours; (3) adding a binder into the powder prepared in the step (2), granulating, then pressing for forming, and finally sintering at 700-750DEG C in the air atmosphere for 4 hours; the binder is a polyvinyl alcohol solution with the mass concentration of 5%, and added polyvinyl alcohol accounts for 3% of the total mass of the powder. The prepared dielectric ceramic Li2Zn2W2O9 can be well sintered at 700-750DEG C, the dielectric constant reaches to 19-20, the quality factor Qf value reaches as high as 67000-82000GHz, the temperature coefficient of resonance frequency is low, and the dielectric ceramic has great application value in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a dielectric substrate, a resonator, a filter and other microwave components used at microwave frequencies, as well as a dielectric ceramic material for a ceramic capacitor or a temperature compensation capacitor 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...

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 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, and the τ of single-phase microwave dielectric ceramics with low inherent sintering temperature ? Usually large, can not meet the requirements of device thermal stability, which largely limits the development of low temperature co-firing technology and microwave multilayer devices

[0011] It has been reported in the literature that the composite oxide Li as a cosolvent for ZnO single crystal growth 2 Zn 2 W 2 o 9 Synthesis, structure and thermal properties of , so far there is no research and report on its microwave dielectric properties

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