SU1728189A1 - Piezoelectric ceramics material - Google Patents

Abstract

The invention relates to radioelectronic materials and can be used in the manufacture of piezoelectric high-frequency acoustic transducers. To reduce the dielectric constant and increase the piezoelectric module (3, the piezoelectric ceramic material additionally contains TE205 and SG203 in the following ratio of components, wt.%: 47.76-52.17; MoO 11.78-13.98; PHO 11.41-13.34 ; Ta205 22,24-26,82 and Сg20з 0.2-0.3, obtained by the following method: synthesis at 700 ° C, 4 hours; sintering at 940-945 ° C, 1 hour; the material has the following characteristics: e 40-50; tgd 0.004-0.006; bcc 9.1-10.3 C / H. 2 tab.,

Description

sl C

This invention relates to piezo engineering and may be used for high frequency acoustic transducers.

The known piezoceramic materials with a layered perovskite-like structure have relatively high dielectric constant values (Ј above 100). So, for ceramics containing K20, BlaOa, TlOa and A / O oxides, the dielectric constant is 105. Piezoceramics containing oxides are .В120з. TiO2, LYuZ and / or NbaOs, TaaOs, has e 110-140. The material containing PbO, V120z, TJ02, NbaOs and L / Oz. dielectric constant is 150.

The closest technical solution to the proposed one is a non-carbonaceous material containing wt.%: PHO 24.45, 51.04, TiO2 8.75 and MoO 15.76, The disadvantage of this ceramics is the relatively high dielectric constant (80 UHHz frequency).

The purpose of the invention is to reduce the dielectric constant and increase piezomodules.

The goal is achieved by the fact that a piezoceramic material including Pb0, MoO3, additionally contains Ta20s and CgCO3 in the following ratio of components, wt.%:

Ply11.41-13.34

V120z47,76-52.17

MOZ11.78-13..98

TazOb22,04-26,82

Сг20з0,2-0,3.

The use of Cr20z is known for the purpose of enhancing piezoelectric modules.

Ceramics are produced by the method of conventional ceramic technology from oxides of lead, bismuth, tantalum, molybdenum and chromium

vj go with

00

Yu

(all grades are x.a.) - Mixing and grinding the components is carried out in a drum drum in isopropyl alcohol, grinding time 20 hours. The slurry is dried at 150 ° C, pressed into briquettes under a specific pressure of 800 kg / cm3 and synthesized at 700 ° 4 hours. After being ground for 24 hours in isopropyl alcohol, dried slip into discs with a diameter of 12 mm and a thickness of 2 mm. A 3% aqueous solution of polyvinyl alcohol is used as a binder. Sintering is carried out at 940–945 ° C, with an exposure of 1 h. Electrodes are deposited on ground disks by sputtering aluminum in a vacuum. The polarization is carried out in a polysiloxane fluid at 150 ° C and a field strength of 50-70 kV / cm.

The chemical composition of materials developed according to the described technology is given in Table 1. . Ceramic (GOST 473.1-81) and electric (GOST

12370-80) properties of materials and prototype (PR) are given in table 2. Compared with the prototype, the value of the dielectric constant of the proposed material is reduced by almost half. At the same time, the value of the piezoelectric module das is slightly increased. The proposed material can be used as high-frequency acoustic piezo transducers. The material was tested and gave positive results.

Claims (1)

Invention Formula Piezoelectric ceramic material, including BlaOs, MoO3 and PHO, characterized in that, in order to reduce the dielectric constant and increase the piezoelectric module, it additionally contains Ta20s and Cr20z in the following ratio of components, wt.%: B120347.76-52.17; Mooz11,78-13,98; PHO11.41-13.34; Ta20522.24-26.82; Сг20з0,2-0,3. Table 1 table 2