JPS59108380A - Piezoelectric material - Google Patents

Abstract

PURPOSE:To produce the titled material easily polarized with low and minute porosity applicable in the high frequency region by a method wherein the composition thereof is specified by major component of Pb, TiO3 containing La, Bi, Nb with MnO2 added thereto. CONSTITUTION:The titled material is composed of Pb, TiO3 as major component containing La, Bi, Nb with MnO2 added thereto to be represented by the composition expression as formula I . Where: the values of x, y, z are respectively assumed to be x=0.01-0.10, y=0.02-0.10, z=0.1-0.5. For example, PbO, TiO2, Bi2O3, Nb2O3, MnO2 are weighed into specified composition ratio to be mixed evenly as the material. The material is calcined and after being milled by a ball mill etc., the resultant powder with a bit of binder such as water or polyvinylalcohol etc. added thereto is made even by passing it through a sieve to bake the green compact formed by the pressure of 0.5-1.0ton/cm<2> producing a piezoelectric ceramics by means of polarization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ceramic housing material, and more specifically, relates to the modification of an FE housing containing lead titanate tub Ti IJ@J as a main component.

Conventional EEt body H material and L, pb (Zr, 'ri) (
h tt I'Jbg(Js.

Piezoelectric materials with improved royal properties by adding various additives such as k'e*()s, and tricomponent piezoelectric materials made by solid-dissolving composite perovskite in Pb(Zr, Ti)(Js) have been developed. It is used in a wide range of fields, such as ultrasonic vibration elements, ceramic fin letters, EE direction force sensor elements, etc.

L 7)) L #b; Gr, this t;, l'b
(Zr, 'ri) (Js-based 1f'llC body material has a large inducement* of about 1000 in this R, and when used at high frequencies, the input/output impedance of the element decreases and the connection with external connection circuits is high.) There is no problem that it becomes difficult to achieve isopedance matching.Also, Pb(Zr, 1!i)(J
For the s-based FTE housing material, the thickness vibration σ) coupling coefficient It and the spreading vibration coupling coefficient Np have approximately the same value of +15.If you try to use the thickness vibration at high frequencies, the spreading vibration O) Ohno: ``The problem arises that a single tone causes vibration suborious.

On the other hand, since pbTiOs has a small dielectric constant of about 200, it is easy to achieve impedance matching in the high frequency range, and furthermore, the thickness vibrational coupling coefficient Kt is spread out and is larger than the vibrational coupling coefficient Lp, so that subria frequency occurs at high frequencies. It has the characteristic of being difficult. However, PbTiOs has better sinterability. , - points, making it impossible to obtain a dense sintered body, and furthermore, the outside conditions were 200
It was difficult to put it into practical use because it required the application of an electric field of 1ull KV/e1M or more at a temperature of 100°C or more, which was very severe.

The purpose of the present invention is to improve the above-mentioned drawbacks of I'bT'i08, to make it suitable for use in the high frequency range, and to have a less porosity and a less dense structure than conventional ones. ,
In addition, we are a company that provides Pb'l'1lJs-based piezoelectric materials that can be easily separated.

The FEW body material according to the present invention has l'b'l"1 (Ja
This is a PbT'1 (Ji 2 -based piezoelectric material) characterized by containing lanthanum (La 2 ), bismuth (BiJ, and niobium (Nb)) as a dry component, and adding a small amount of manganese dioxide (MnUt 2 ). La,
When feeding Bi and Nb, take into account their ionic radii.
Assuming that La is 81i, Hi is octavalent, and Nb is pentavalent, the compositional formula of the royal body material of this investigation is (Pbl-7La!/
17) ((Bi1/2N111/2JXTil-008
The IFg member was synthesized as +1% by weight M-Ot.

-8-- The present invention will now be explained in detail.

The piezoelectric material of the present invention can be manufactured by conventional powder metallurgy techniques. In other words, the raw material and 1- are one thing].

TiUx, )jig(Js, Nbt06.LazU
s, MnO20) Illide is accurately weighed to a predetermined ratio FI<, and the mixture is uniformly mixed using a ball mill or the like.

For example, to explain the blending ratio for the composition of Sample Black 7 in Table 1 of the Incursion, the direct supply of the entire raw material is 100 toshite Pb.
L), 'I'it)g, Li5t)s, BitlJs,
Nb2U11 were 68.7 and 25.1, respectively. 2
．． 5B, 1.92. They were accurately weighed and blended at a weight ratio of 1.75, 0.2% by weight of MnUg was added thereto, and mixed uniformly using a ball mill or the like.

Note that the raw material is not limited to oxides in particular, but may also be compounds that can be converted into oxides by firing or heating, such as hydroxide, carbonate, 7491w salt, etc. First, the raw materials are placed in a high-purity aluminum crucible. After calcining at a temperature of 800 to 900°C and further pulverizing with a ball mill etc., the obtained 6.
1. Add a small amount of water or a bisider such as polyvinyl alcohol to the powder, stir, and pass through a sieve. OLon/c
d) Shape with If force to form a green compact. This green compact was hermetically loaded into an aluminum crucible and heated to 1180° to 1° in an electric furnace.
It is fired at a temperature of about 25o' to form porcelain.

Holding at the maximum temperature for about 0.5 to 2 hours is usually sufficient. The thus obtained porcelain was heated in silicone oil at 100-160'C for 40~(iQKJ//&s electricity (1)).
After applying shade treatment, the product is made into a product.

In this way, the composition formula Pb(1-y) La! /my
[(mountain I/2(7 Nb+/i)
We made a sample containing additives, and the obtained sample complied with the Japan Electronic Materials Industries Association Standards EMA8-6001 and EMA6001.
Coupling coefficient K of spreading vibration according to the method described in 008
The EE characteristics and mechanical properties of the combined body of thickness vibration @V, t, etc. were measured. Also, calculate the density of the fired body by the buoyancy method.

The porosity etc. were determined. Furthermore, the dielectric constant was measured using a 111z AC bridge. Regarding those measurement results,
Put it on the table. (In addition, in the table, 1 mark is added to the boiled sample.
As is clear from Table 1, sample 12 is an example of the present invention.
Bi, Nb to li! In the case of transmutation, Di,
By containing Nb, dense porcelain with low porosity can be obtained, but l:E! Poor electrical performance.

Test F48 is an example of PbTi (Js + c La containing Wt#), and an improvement in electrical performance was observed due to the inclusion of La, but a dense one with a large porosity was obtained. (Cutter. Regarding all containing Di and Nb, compared to sample 4, when 1+ Since a magnet with good density and FE! performance was obtained, it was confirmed that Although relatively good porcelain can be obtained with this composition, if the porcelain is left at 11- for several cycles after fertilization,
In the @ vessel, l1Ilt1 occurs, and there is a gap of 1 in the stability of the porcelain.On the other hand, in the case of X = O, t in sample 8, there was no such four terms, so the value of X was set to be less than O1. Preferably.

Furthermore, regarding the content of La, sample 10 has Y = u, ot, and the piezoelectric performance is the same as 9 and -4, while sample 11 has Y = 0.02. in the case of,
Since we have obtained a porcelain that has the performance of 1K 11L in terms of light, Y
The value of (old) was set to be 2 or more. Also, from sample 18, Y =
In the case of 0.2, it is not possible to take advantage of the advantages of PbTiOs that the permittivity is attractive and the matching of I'/beadance is brown at high frequencies. Since this did not occur in the case of , it was concluded that a value of Y exceeding 01 is not desirable.

Regarding the addition of 3g of MnL, 2 = from trial 14414.
In the case of 005, the porosity is large (dense m-cells cannot be obtained,
On the other hand, compared to sample 7, when z=01, the porosity is small @
In the swamp, a 11d device with good Ff performance was obtained.
From this, it was confirmed that 2 needs to be between 01 and 7. Also, compared to Sample 16, when Z = to, only porcelain with large porosity and poor EE performance was obtained; on the other hand, when Z = 0. In Ii, a fine porcelain with excellent quality is obtained, so the value is set to 2 (preferably 15 or less).

Sample 5~f3, 11.12.15 gives yen + ['i
By adding MnUg to 0s with Pb (mountain 1/2Nb+/1) (Js and La fixed at the same time), +41 electricity with small porosity and denseness and excellent piezoelectric performance was created. Furthermore, from sample 6.7, it can be seen that 1 mo of the present invention [material is 1150 to 12+10
It has a relatively wide temperature range of 'c' and has a relatively wide temperature range of
Firing of TiUs/I! It can be seen that the dark range is very narrow and sintering is difficult, but it is easier to manufacture porcelain at L.

Based on the above experimental results, in the present invention, when the compositional formula % formula %' is expressed as the amount %MnUz, the former of +rH,
Substitution with Nb @X to 0.01 to 0.1 and Pb
(D La substitution Y by 0.02 to (1,11
0 ni, MnC) x O') attachment mtz'@fune 01~0
Limited to 5.

That is, in the H f composition, when X < 0.01, the sinterability is poor and M + dense porcelain cannot be obtained, and when X > O, t, the mechanical strength of the sintered body decreases and the sintered body becomes a compact. This is because cracks tend to occur and cannot withstand mechanical processing.

9- -4 r: Pb o) La +t Yoro substitution dragon Y to 0
．． 02-0.10 is less than 0.02, the same as the EE electric performance of the material is not seen, and the Phi
'i
This is because the effect of IT exchange is not seen very much, and since 02
Replacing it with invites! This is because there is a tendency for the temperature stability T property to deteriorate as the * becomes higher.

The reason why the 2% by weight of Mn 01 added is limited to 0.1 to 0.5 is because it is difficult to obtain dense porcelain with good electrical performance in the range less than 01 or in the range 1.0 or more.

According to the present invention, the following effects can be obtained.

1j! Conventionally, PbTi01 alone had poor sinterability and it was difficult to obtain a porcelain that could withstand practical use; however, the material composition of the present invention widens the sintering temperature range, and
Please make the sintering of I-ware easier. For this reason, PhTi0@ system pE is extremely dense and mechanically strong! Body material is obtained. Conventionally, when PbTi0m alone was used as fR2, it was very difficult to obtain a ray cone, but the inventive material composition makes it possible to easily obtain a shade.

That is, to separate the conventional PbTi (J++), 1
Over 00℃! Although it is necessary to apply an electric field of 10 tl KV/as or more at IF and t, the BE ton rod material according to the present invention can be be. Therefore, Pb'l' has a low M electrical conductivity and the coupling coefficient Kt of thickness vibration is larger than the coupling coefficient Kp of spreading vibration.
Be able to bring out the characteristics of i0* easily and fully.

As described above, according to the present invention, a sintered body that is dense and dark enough to withstand mechanical processing can be easily produced by ordinary powder metallurgy techniques. Since the coupling coefficient QKt of the thickness vibration of the body material is larger than the coupling coefficient Kp of the spreading vibration, spurious noise is generated at high frequencies, and furthermore, the electrical conductivity is low by #%.
It has the advantage of easy impedance matching at high frequencies, and is particularly useful for high frequency applications, such as high frequency filters and high frequency resonators.

11- 420-

Claims (1)

[Claims] The main component is titanium (pb'C1ym), lasotan CL&)t bismuth (or niobium (Nb)).
Contains manganese dioxide (MnlJ!)
In the field ridge material, the formula is (pHl -y Lag/ay month: (Hi +/1Nb
When j4)xTi +-x)tJs+ is expressed as weight%M]02, the values of X and engineering 2 are,! = (1,01~0
10°y = 0.02~0.10. z = 0.
1-0.5 and 1. r: A stopover material characterized by c.