SU666154A1 - Non-linear ceramic dielectric material - Google Patents

Description

(54) NONLINEAR CERAMIC DIELECTRIC LITERIAL

The invention relates to KepaNmnec-KIM materials having a high dielectric non-linearity and induced piezo-activity when a permanent electric FIELD is applied; The proposed material can be used as a functional element with controlled capacitance and controlled piezoelectric characteristics in various radio engineering devices.

Ceramic materials of variconds based on ferroelectric compounds of the oxygen-octave type, which produce the induced pie-up effect 1, are known.

However, their dielectric nonlinearity is relatively small.

The closest technical focus to this is a nonlinear kerak dielectric containing PbO, MgO. .LijOUI with the following ratio of components (wt.%):.

РЬО61,81-67,29

36-8.51

NbjOg24,02-31,67

, 16-0.18

The disadvantage of this material is the low values of dielectric nonlinearity, 1 which does not allow efficient control of weak fields with a capacitance of a NieHTOB element made of this material. Low dielectric constant values, along with low nonlinearity, do not allow to achieve high characteristics of induced piezo activity.

The aim of the invention is to increase dielectric nonlinearity and induced piezo activity.

This goal is achieved by the fact that a non-linear ceramic dielectric material containing PbO, MbgOg Zi.O, additionally contains ZnQ in the following ratio of components (wt.%):

Pb67.80-67.86

26.93-26.95 O, 05-O, I4 1.98-2.15

The material is obtained by conventional ceramic technology by two-stage firing. Metal oxides are used as starting components. Pre-stage firing temperature is 71О-73О ° С with holding time. When cooking elements of this

The final sintering temperature is 1220-1240 ° C with an exposure time at a maximum temperature of not more than 1 hour. Lithium oxide is introduced above stoichiometry to improve sintering of the resulting products. Electrophysical characteristics of the prepared materials containing (weight,%): PHO - 67,913; MgO-3, O NbjOj- 26.94; ZnO - 2, O7, L O, O 9, are tabulated.

Claimed Perov-10-13 (16-18) yu material skit

TO- Curie temperature

E - dielectric constant in the absence of the floor - - dielectric constant s saw

p the nonlinearity coefficient p -100%

piezo module

31

TKf temperature coefficient of resonance frequency

Claims (2)

2 square of electromechanical coupling coefficient. Q - mechanical soundly The above-mentioned ratios of the initial components are optimal since the selected composition is ia concentration v boundary of the solid solutions system bMgj, Hbj jOjPbZn ,,, D At which maximum values of the dielectric constant and its nonlinearity are observed. The ia graph shows the concentration dependences of the peak values of dielectric permittivity n (the maximum nonlinearity coefficients at a frequency of 1.51 OHz, and the induced piezoelectric effect coefficients N at a frequency of 3 Hs, as well as the parameters of the elementary cell and Curie temperature. the magnitudes of its nonlinearity and the characteristics of the induced piezoactivity allow using the claimed material as a functional element with controlled electric field, capacity and 3.7.-3.9 O 4-10 0.08 6-10 800 bezoso-vstvami. With greater efficiency. Claims of the invention The nonlinear ceramic dielectric material containing PHO, HbjD jLi20, characterized in that of dielectric nonlinearity and induced piezoactivity, it additionally contains ZnO in the following ratio of components (wt.%) -: PbO67.80-67.86 MgO3.03-3.11.11 NbjOg26.93-26.95 LijO0.05-0.14 2nO1.98-2D5 Sources of information taken into account during the examination 1.Zhukovsky V.N., et al., Electronic equipment, series 6, No. 9, 1975, p. 129. 2. USSR author's certificate number 434071, cl. C 04 B 35 / OO, 1974, P) Pnd, 1 NbsljO - „on% S f / jUbi OjliJI 0 0 so ev