JPS63144165A - Oxide ceramic material for piezoelectric element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to oxide porcelain materials for use in focused TL devices.

As is known, LiTaO s is used as a material for pyroelectric elements.
, PZT, TGS, SBN,
There are P b T i Os and the like.

However, these materials are difficult to manufacture and have drawbacks in their properties.

Among these, -C, which is a pure PbTi0jBi material, has great performance potential as a material for pyroelectric elements, but due to the strictness of manufacturing, products with sufficient performance have not yet been produced.

We are proud of the high quality of Pb TiOs porcelain! Because PbTiOs has excellent physical properties that are essential for use as an element material (large pyroelectric coefficient, low dielectric constant, high Curie point), specific modification is performed on PbTiOs. Therefore, the object of the present invention is to provide an inexpensive and high-performance sinter element material that is easy and stable to manufacture and is suitable for mass production.

Pure PbTiOs porcelain is extremely difficult to sinter, so attempts have been made to obtain high-density porcelain using additives and the like.

Among various experiments, we conducted experiments on (Pbl-1・Ca,) [(M
n 1/2 ・S b 1/2) Y-T l +-
Yko0. Oxide porcelain with a composition expressed by ξ is homogeneous, dense, l] and burnt! I learned that it has sufficiently high performance as a material for elements.

This invention will be explained below by giving examples.

Chemically high-purity powder raw materials PbO, Ca as starting materials
CO= Mn COs (or MnO+), Sb'r
Ol and Ti○ are weighed in a predetermined ratio and mixed in pure water using a ball mill for 20 hours.

After drying this raw material for 7 minutes, it was pre-calcined at 800°C to 1000°C for 1.5 hours.

Since there is a risk that a portion of the PbO may evaporate during pre-calcination, a dense alumina sagger was used and the PbO powder was placed in the case together with the sample.

Next, the sample produced by this pre-calcination was ground in a ball mill to produce V4 powder of 0.5 to 2.0 μm.

An appropriate amount of an organic binder such as PVA or pure water was added to the mixture to form granules, thereby obtaining a raw material for molding.

Using this molding raw material, it was made into a mold with a diameter of 15 cm and a thickness of 1.5 mm.
Pressure mold the disc at 1 ton/cm.

This molded product was placed in a six-pot sagger pot with a higher airtightness than that used for pre-firing, and fired at 1000°C to 11SO°C2 for 1 hour.

The sintered body thus obtained is polished to a predetermined thickness,
Silver electrodes were provided on both sides by vapor deposition.

Then, apply 5KV for 30 minutes in silicone oil at 100℃.
Polarization was performed by applying a DC voltage of /m.

In addition, the infrared detection koi! In order to use it as an element, this sample was polished to 60 μm and cut into 3 m x 2 mm, and electrodes were provided with nickel, aluminum, etc. by vapor deposition.

The relative dielectric constant of the sample obtained through this process was determined at room temperature, and the pyroelectric coefficient was determined in the temperature range from -20°C to 60°C.

(Example 1) Sample number 1 Prepare the sample according to the above steps.

When the molar ratio of Ca is less than 0.10, sintering is extremely difficult, and the fired product does not undergo efflorescence.

The molar ratio of (M nl/2 ・S bl/2 ) is 0.
When the sintering temperature exceeds 01, homogeneous sintering becomes difficult, and the state differs between the surface and the inside of the sintered body.

(5! Example 2) Sample number 32 Prepare the sample according to the above steps.

When the molar ratio of Ca exceeds 0.40, ir becomes large and the pyroelectric coefficient also becomes small, so that the pyroelectric element loses its usability as a tower.

Also, the molar ratio of (Mnl/2 ・S bl/2 ) is 0,
If it exceeds 25, it is a specific resistance! becomes smaller and polarization becomes difficult.

Even if polarization is possible, the pyroelectric coefficient tends to decrease, making it useless as a pyroelectric element.

Table 1 shows the properties of the uninvented oxide ceramic material for pyroelectric elements.

For reference, PZT-4, 5ro, a from among the conventional materials
,'B1La,s+'Nb*Os are also written.

The above-mentioned (Example 1) and (Example 2) are compositions that show the limits of effectiveness in terms of manufacturing and properties as a material for a fiber optic T of the present invention.

Furthermore, a part of the material must have a sufficiently high Curie temperature to withstand practical use, which is an essential condition for use as a pyroelectric material.

The following is a list of selected samples and examples of Curie Onno'hi.

Trial test li @ l ・ ・ ・ 372 °
C 7 ・ ・ ・ 338 ℃ 3...
・296℃ 20...236℃ 28...184
℃ Same 32...148℃ Same 28...184℃ Same 3
2...Since the temperature is 148°C or higher, the material for the pyroelectric element according to the present invention has superior properties compared to conventional materials, and also does not require expensive raw materials from an industrial standpoint. As for manufacturing, homogeneous and dense porcelain can be easily obtained using common ceramic methods, making it possible to provide materials for inexpensive, high-performance porcelain elements, which can be expected to have industrial value.

Claims (1)

[Claims] (Pb_1_-_x・Ca_x) [(Mn1/2・Sb
1/2)_y・Ti_1_-_y]O_3 An oxide ceramic material for a pyroelectric element, characterized in that x and y are in the following ranges in the basic composition represented by: x=0.10~0.40 y=0.01~0.20