A kind of titanium iron niobate copper bismuth giant dielectric ceramic material and preparation method thereof

Abstract

The invention discloses a titanium iron niobic acid copper bismuth giant dielectric ceramic material and a preparation method thereof, a general formula BiCu3Ti3Fe1-xNbxO12 is used for expressing the composition of the ceramic material, in the formula, x is greater than or equal to 0.3 and less than or equal to 0.9, and processes of preparing the raw materials, pre-burning, granulating, tabletting, sintering, and firing silver can be carried out for preparing the giant dielectric ceramic material. The experiment result shows that by increasing the Nb content, the crystal grain resistance of the ceramic material is decreased, a dielectric constant platform and a dielectric loss peak move towards to a high frequency direction, when x is 0.9, the dielectric constant of the ceramic material under room temperature is highest, the dielectric constants are 29010 and 7300 at 1kHz and 100kHz, when x is 0.6, dielectric constant is 6185 at 1kHz, and the dielectric constant is 3650 at 100kHz, and the dielectric constant has good frequency stability at a frequency scope of 40kHz-100kHz under room temperature, when x is 0.4, the dielectric constant has good temperature stability at 1kHz under a temperature scope of 30-420 DEG C.

Description

technical field [0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a dielectric ceramic material used for storage or capacitor devices and a preparation method thereof. Background technique [0002] In 2000, Subramanian and his working group first synthesized BiCu 3 Ti 3 FeO 12 (abbreviated as BCTFO) dielectric ceramic material, the dielectric constant and dielectric loss of the material are 692 and 0.082 respectively under the action of 25 ℃ and 100kHz AC electric field. In 2005, United States Patent reported BiCu 3 Ti 3 FeO 12 It has good dielectric tunability and low loss in the frequency range of 10kHz to 100MHz, and can be applied to phase converters, filters, oscillators and resonators. It can be seen from the above reports that due to the BiCu 3 Ti 3 FeO 12 There are +2 and +3 price changes of Fe element in ceramics, which inhibits the price change of Ti element trivalent and tetravalent, resulting in increas...

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Problems solved by technology

It can be seen from the above reports that due to the BiCu 3 Ti 3 FeO 12 There are +2 and +3 valence changes in the Fe element in ceramics, which inhibit the valence changes of the trivalent and tetravalent Ti elements, resulting in an increase in grain resistance, and no giant dielectric constant platform can be observed at room temperature and in the frequency range of 40Hz-110MHz , the dielectric constant is low, and the inventor's research group found through experiments that BiCu 3 Ti 3 FeO 12 Ceramics have poor dielectric constant frequency stability in the frequency range of 40Hz-100kHz at room temperature; at 1kKz, they have certain dielectric constant temperature stability in a narrow range of 100°C-300°C

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