JPS60102779A - Piezo-electric ceramic composition - Google Patents

Abstract

PURPOSE:To make larger the value of electric machine coupling coefficient of the radial oscillation and the permittivity of the titled composition by a method wherein, in the three component systems of PbO3-PbTiO3-PbZrO3 of the composition, a part of the Pb is substituted for Sr or Ba, and at the same time, oxides such as an Ni, etc., are added to the fundamental composition. CONSTITUTION:In a piezo-electric ceramic composition to three component systems of Pb(Mg1/3Nb2/3)O3-PbTiO3-PbZr3, a part of the Pb is substituted for at least more than one atom chosen from a group of Sr or Ba, and at least one kind of Ni, Ce and Y is added to the fundamental composition at a ratio of 0.1-7.0wt%. By composing in such a composition, the purposive piezo-electric ceramic composition, whose electric machine coupling coefficient of radical oscillatin becomes a large value of 45-65% and moreover permittivity becomes a very large value of 3,000-7,000, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric ceramic composition having a large electromechanical coupling coefficient for radial vibration and a large dielectric constant ε33.

Traditionally, ceramic materials that are solid solutions of lead titanate and lead zirconate are ceramic materials that exhibit large piezoelectric and electrostrictive effects in the vicinity of compositions that exhibit a morpho-1 to Robic crystal phase transition, and various additives have been added to these ceramic materials. to improve physical and electrical properties.
The diluted material is widely used instead of barium titanate. In particular, Pb (MIJ7.N11)03
Piezoelectric ceramic compositions consisting of a three-component system of PbTi03PbZrO3 have been improved in piezoelectric properties by various substitutions and additions, and have been widely applied.

However, although these piezoelectric ceramic compositions have a large electromechanical coupling coefficient 1<P of radial vibration of 50 to 70,
All of the dielectric constants ε were small, ranging from 1000 to 3200, which was insufficient to obtain large mechanical vibrations and displacements.

An object of the present invention is to improve the drawbacks of the prior art described in -1- and to provide a piezoelectric ceramic composition having both a large electromechanical coupling coefficient kF of radial vibration and a large dielectric constant ε.

The present invention HaPb (M!117 Nb7) Oa Pb
In the TiO3Pb Zr Oa ternary system, pb
- part is replaced with 3r or Ba, and at the same time N i ,
Ce.

It is characterized in that at least one type of oxide of Y is added, and M1102 is not added.

By replacing a part of Ph with Sr or Ba,
The sinterability is improved, and by adding at least one of Ni, Ce, and Y oxides without adding MnO2 at the same time, the electromechanical coupling coefficient of radial vibration can be increased to 45 to 65%. It is large and has a dielectric constant ε of 300.
A very large number of 0 to 7000 was obtained.

The present invention will be explained in detail below with reference to Examples.

Figure 1 is a triangular diagram showing the basic composition of the present invention.
O5, T! 02. After weighing ZrO2 and BaC03NiO and performing wet mixing using a ball mill, 400 k
g/am2 and calcined at 850°C for 2 hours.

The calcined product was mixed 24 hours a day again using a ball mill, then further crushed using an agate mortar, and after adding distilled water to make it homogeneous, it was mixed at 700 k(]/cm' for 20 min.
It was pressure molded into a φ mold and main firing was performed at 1200 to 1300°C for 45 minutes. After measuring the density of fired porcelain,
Cut to diameter 16φ and thickness imm.

After polishing, the Cr-Au electrode was vaporized and polarized in silicone oil at 120 °C with a DC electric field of 40 kV,
Measurement test 1'N1 was used.

Tables 1 and 2 show some of the compositions and dielectric and piezoelectric properties of the porcelain obtained according to the present invention.

Even when 0.1 to 7.0% by weight of an oxide of Ce, etc. was added, the same bonding as that of Ni was obtained. Also, further A
Adding 0.1 to 1.0% by weight of l2O3 can improve the mechanical strength without deteriorating the electrical properties shown in Table 1. As shown in the above embodiments, the piezoelectric ceramic composition according to the present invention has a radial vibration electromechanical coupling coefficient of 1 compared to conventional products.
(It is clear that both the dielectric constant ε and the dielectric constant ε are large, and it exhibits immersed characteristics.

[Brief explanation of the drawing]

FIG. 1 is a triangular diagram showing composition ranges in Examples of the present invention. No./Figure Pb (19 stations %) 08 pb million OJ Pb2: r03 -7 = 1981 Patent Application No. 21051, Title of invention Relationship to the case of person who corrects piezoelectric ceramic composition Patent applicant address Chiyoda, Tokyo Ward Marunouchi 2-1-2 Name (5
08) Hitachi Metals Co., Ltd. Telephone: Tokyo 03-284-4642 "Detailed Description of the Invention" column of the specification. Contents of amendment 1: The statement in the "Detailed Description of the Invention" column of the specification is corrected as follows. (1) “Dielectric constant ε, 1.” on page 1, line 18 of the specification is [
Correct the dielectric constant to εX/EoJ. (2) "Dielectric constant εL" on page 2, line 12 of the same book is corrected to [relative permittivity ε=/g, J. (3) "Dielectric constant εL" in line 16 of the same page is corrected to [relative permittivity εhzg, J]. (4) In the same book, page 3, line 9, "dielectric constant εL" is corrected to "relative permittivity ε crystal/eo J." (5) In the same book, page 5, table 1, "εu3" is changed to " ε33/E
Corrected to 6. (6〉In Table 2, page 6 of the same book, ``ε;
J: Corrected to ``The composition is the same as the conventional product.''

Claims (1)

[Claims] 1, X P b (M'I I/3N b example>0
3 Pb atom f7 of VPbTiO3-ZPbZrO3 system
) 20 atomic % or less Add at least one type of oxide of Ni, Ce, Y to the basic composition consisting of a solid solution substituted with at least one atom selected from the group 3r, 3a.
A piezoelectric ceramic composition characterized in that it contains ~7.0 weight% (where x-0,69 ~ 0,125. V =
0.3・-〇, 52, Z = 0.01~0,57
5. X + V + Z = 1.00). 2. A piezoelectric ceramic composition according to claim 1, characterized in that 0.1 to 1.0% by weight of the oxide of A1 is added.