JP2000127392A - Lead based dielectric ceramic and actuator employing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lead based dielectric ceramics generating a field induction strain suitably employed in an actuator by eliminating virgin strain and residual strain, setting Curie point higher than an actual working temperature and increasing displacement or strain being generated upon application of an electric field. SOLUTION: A lead based dielectric ceramics has principal composition shown by formula I where 0.065<=x<0.10, 0.60<y<0.80, 0.40>z>0.20 and Ba, Sr are partially substituted, as subcomponents, for lead. The lead based dielectric ceramics can be executed within a limited compositional range of PLZT ceramics and barium, strontium elements having substantially equal ion radius substitute for a part of lead element in order to limit the compositional range and to stabilize the characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-based dielectric ceramic which generates a large amount of displacement when an electric field is applied, and an actuator such as an ink jet printer head using the ceramic.

[0002]

2. Description of the Related Art Conventionally, PZT ceramics or the like has been used as an actuator for an ink-jet head of an ink-jet printer (for example, see Japanese Patent Application Laid-Open No.
No. 20726, JP-A-7-132597)
However, the performance of ceramics was not sufficient to further increase the performance and density of the actuator.

[0003]

When an electric field is applied to a lead-based dielectric ceramic, electric distortion occurs. This phenomenon is explained by three types of strains from solid-state physics: strains due to the inverse piezoelectric effect, strains due to the electrostriction effect, and strains due to the electric-field-induced forced phase transition. Such elastic deformation is an important device function in terms of engineering as a solid actuator of an electromechanical transducer, and there are many types of applied products. The most required characteristic of the actuator is that the amount of displacement generated when an electric field is applied or the amount of distortion obtained by dividing the amount of displacement by the original length is large.

[0004] The present invention has thoroughly examined the above three types of distortion phenomena, and as a result, has found a material which gives an unprecedented large distortion. The inverse piezoelectric effect is to give a strain in direct proportion to the applied electric field strength, and lead zirconate titanate;
There is a material known under the name ZT. This distortion is 0
It gives a maximum of 0.15% distortion at 20 kV / cm drive. The electrostriction effect means that a strain proportional to the square of the electric field strength is given to lead magnesium niobate-lead titanate solid solution;
There is a material known under the name MN-PZT. This distortion amount is 0.09% at maximum under the same conditions. The present inventor has described the electric-field-induced forced phase transition in “Jpn.J. Appl.
s. Vol. 36 (1997) 5997 ", which is a lead stannate-modified lead zirconate titanate (PNZST) material. This strain gives 0.44% strain when 80 kV / cm is applied. This is a much larger value than the strain found in conventional actuator materials.

[0005] However, the forced phase transition has a threshold electric field at which distortion occurs, and does not generate distortion under a practical driving environment at about 20 kV / cm or less. When the origin of various strains was measured for the purpose of obtaining a huge strain, it was found that there were two types of strains limiting the strain of each material: virgin strain and residual strain caused by domain motion of ceramics. The “virgin distortion” and “residual distortion” will be described later.

[0016],

The details will be described in [0015].

Although an electrostrictive material having no insensitive distortion to these two drive voltages is promising, the electrostrictive material has a Curie point near room temperature and its displacement is drastically reduced even with a slight temperature rise. Has the disadvantage that For example, the aforementioned PMN-PT (composition 0.9 Pb (Mg _1/3 Nb)
The Curie point of _2/3 ) O ₃ -0.1PbTiO ₃ ) exists at 24 ° C., and at 50 ° C., the amount of strain is halved. This means that the distortion effect is reduced and the temperature characteristics of the element are insufficient.

[0007]

According to the first aspect of the present invention, there is provided a lead-based dielectric ceramic which generates an electric-field-induced strain, has no virgin strain and no residual strain, and has a Curie point higher than an actual use temperature. The present invention relates to a lead-based dielectric ceramic characterized by the following. This lead-based dielectric ceramic is a material having the characteristics of an electrostrictive material and exhibiting a piezoelectric behavior, in other words, having no virgin or residual strain, and having a Curie point at around 70 ° C. above room temperature. The present invention relates to a dielectric ceramic.

According to a second aspect of the present invention, the main composition of the lead-based dielectric ceramic according to the first aspect is represented by the following formula:

[0009]

(Equation 2)

0.065 ≦ x <0.10, 0.60 <y <0.80, 0.
40>z> 0.20, and Ba, S
The present invention relates to a lead-based dielectric ceramic in which r is partially substituted with lead. This lead-based dielectric ceramic can be implemented in a limited composition range of PLZT ceramic,
The present invention relates to a lead-based dielectric ceramic in which the range is limited, and a part of lead element is substituted and modified with barium or strontium element having the same ionic radius for stabilizing characteristics.

[0011] The invention of claim 3 relates to a lead-based dielectric ceramic in which the relative density of the ceramic of claim 2 is 98% or more. This lead-based dielectric ceramic has a density of ceramics, that is, 98% or more, particularly, in density.
Preferably, the properties are improved by having a density of 99.5% or more.

[0012] The invention of claim 4 relates to a lead-based dielectric ceramic in which the ceramics according to any one of claims 1 to 3 has a flexural strength of 80 Mpa or more. Needless to say, this lead-based dielectric ceramic is applied to an actuator, but the actuator is processed into various shapes depending on the application. In the embodiment described later, the bending strength of the ceramic is particularly important, and it is required that the bending strength is large. The bending strength described herein is a value derived from a normal three-point bending test and its statistical calculation (Weibull plot). The actuator of the ink jet head disclosed in Japanese Patent Application Laid-Open No. 6-320726 has a columnar process corresponding to each nozzle. In U.S.P. Nos. 5, 295, and 487, a similar aspect process is performed on an ultrasonic diagnostic probe. In the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-320726, the aspect ratio (aspect ratio) is particularly high, and its value reaches up to 40. The high aspect ratio is for increasing the amount of displacement, and further improvement is required for increasing the amount of displacement. Alternatively, it is necessary to sufficiently increase the mechanical strength in order to improve the yield of the process. The invention of claim 4 responds to this request.

According to a fifth aspect of the present invention, the ceramic particle size of the ceramic according to any one of the first to fourth aspects is 5 or less.
The present invention relates to a lead-based dielectric ceramic having a size of not more than μm. This lead-based dielectric ceramic is applied to actuators,
Assuming higher densities, both the aspect ratio and its associated minimum lateral feature size must be met. The current processing pitch by the dicer is recognized as 30 μm as the maximum value. If the aspect ratio is 40
The engraving amount (vertical length) when the horizontal length is 30 μm is simply 1.2 mm. At this time, if the ceramic structure exceeds a certain value of crystal grains (hereinafter simply referred to as a particle size), the mechanical strength is extremely reduced. The invention of claim 5 optimizes this particle size.

According to a sixth aspect of the present invention, the lead-based dielectric ceramic according to any one of the first to fifth aspects is used as an electromechanical conversion element, and is processed into a desired shape.
The present invention relates to a lead-based dielectric ceramic formed by disposing a liquid chamber, a liquid chamber flow path, and a nozzle. This actuator is preferably a device suitable for application of the lead dielectric ceramics according to claims 1 to 5 as an actuator of an ink jet head. Claim 6 relates to exhibiting unprecedented excellent characteristics when applied to this device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows PLZ as an example of residual strain.
T (6.0 / 80/20) and PLZT (7.0 / 80/2)
0) shows the electric field induced strain characteristics. FIG. 1A shows distortion in the case of bipolar driving. PLZT (6.0 / 8
0/20) is a piezoelectric body, while PLZT (7.0 / 8)
0/20) is an antiferroelectric substance, and this characteristic indicates an electric field-induced forced phase transition. Further, in this composition, the phase transition electric field intensity exists at about 25 kV / cm, and no displacement is shown for an electric field lower than that. The maximum strain of the piezoelectric body is 4
At 0 kV / cm, it is 0.17%, and the strain of phase transition is 0.12%. FIG. 1B shows a distortion characteristic of unipolar driving which is close to a condition where the actuator is actually driven. At this time, PLZT (6.0 / 80/20) is 0.1.
% And PLZT (7.0 / 80/20) are 0.17%, and the latter gives higher distortion in driving the actuator. This is due to the fact that the piezoelectric body shown in FIG. 1A shows 0.07% distortion at an electric field intensity of 0. This distortion is called residual distortion. Therefore, the residual distortion amount is a distortion amount insensitive to the drive voltage.

FIG. 2 shows PLZT (7.
5/75/25) and PLZT (7.0 / 80/20) show the strain response to the first drive field. FIG. 2A shows a piezoelectric body in which a strain of 0.11% exists at an electric field intensity of 0. This value is larger than the above-mentioned residual strain, which is obtained by applying the first electric field to the virgin sample, thereby aligning the domains of the piezoelectric substance (ferroelectric substance in a narrow sense) (this is called domain processing). The territory is due to never returning to the initial state. At this time, the distortion caused by the alignment is defined as virgin distortion.
It can be explained that it consists of 04% and residual strain of 0.07.

The virgin distortion is also a distortion amount insensitive to the drive voltage. FIG. 2B shows an example of an antiferroelectric substance, and FIG.
Although there is no residual strain, in this material system, virgin strain accompanying the alignment of the antiferroelectric domains was observed, and the value was 0.07%.
Reach Therefore, these two types of materials having no distortion are preferable for actuator applications. In FIG. 2, the range of the bar shown on the right side indicates the range of the amount of active strain,
The larger this range is, the more preferable the actuator is.
It is presumed that the electrostrictive material does not have these problems because the origin of the strain is different from the domain alignment. However, since it has temperature characteristics as described above, it is not practical. The present invention utilizes the characteristics of the electrostrictive effect and improves the temperature characteristics. Residual distortion and virgin distortion are generated by applying stabilizing energy by domain arrangement.
Therefore, the material should be designed in a state where the arrangement is more stable than the given energy.

In addition, the virgin distortion of the piezoelectric body is often smaller than the residual distortion, and there is an amount that does not need to be considered in the operation of the actuator. Specifically, 5% or less of the maximum distortion amount under the driving voltage is appropriate, and in the present invention, virgin distortion up to 5% or less is defined as not including virgin distortion. The lead element of PLZT ceramics is replaced with another element to improve the characteristics. Barium and strontium having the same ionic radius as lead are suitable as material candidates at this time, and the meaning of the sub-structure is up to 10%.
Corresponds to the substitution

The ceramic of the present invention is prepared by weighing the oxides of the elements constituting the ceramic based on the stoichiometric ratio and performing a solid phase reaction. However, the amount of lead is 5 mol% with respect to the stoichiometric ratio to compensate for the shortage due to evaporation during the process.
Overstocked. These manufacturing procedures are performed as follows. Weigh various oxides to obtain desired composition
The mixture is calcined to obtain a calcined powder, and the main firing is performed to obtain a ceramic. In the main firing, the target ceramic composition material can be obtained without excess or shortage by performing the two-stage firing. The two-step firing is a high-temperature firing (first step) that sufficiently promotes the solid-phase reaction and a step of evaporating excess lead in the case where excess lead is present in the sample. This is performed from the second step performed in time.

FIG. 3 shows an actuator subjected to an aspect processing and an ink jet head function added thereto.
This shows an arrangement in which a diaphragm, a liquid chamber, a liquid chamber flow path, and a nozzle are arranged. The details regarding FIG. 3 will be described later.

The details will be described below. Conventionally, a laminated piezoelectric element is used for the actuator, a piezoelectric displacement part of 150 μm at a pitch of 280 μm, and a length of 6 mm in a separation space of 130 μm.
(Aspect ratio is 40). An electric field is applied in parallel to the polarization direction by the displacement of the piezoelectric body, and the distortion in the direction perpendicular to the electric field application direction generated at that time (in this case,
Negative displacement). Distortion of the piezoelectric body parallel displacement and the applied electric field upon application of an electric field parallel to the polarization axis is associated with the piezoelectric constant d _33, the vertical displacement Δ at that time
z is Δz = d ₃₃ · V (1) The displacement orthogonal to the applied electric field is related by a piezoelectric constant d ₃₁ , and the lateral displacement Δx and Δy at that time are Δx = Δy Δx = x · d ₃₁ E ( 2) E is the electric field strength, and the relationship of d ₃₃ = −2d ₃₁ is satisfied.

A general material constant is adopted as the actuator, and the displacement is calculated as follows. Driving electric field strength 10 kV / cm, PZT piezoelectric constant d ₃₁ = −300
(Pm / V) is substituted into equation (2) to obtain -1.8 [mu] m. According to the equation (2), the displacement can be obtained by using a material having a large piezoelectric constant, by increasing the length of the structure to give the displacement (corresponding to x), or by increasing the electric field strength. The former corresponds to the use of the large strain material amount shown in the first embodiment of the present invention, and the second relates to realization of high aspect ratio processing. The third is the adoption of a laminated piezoelectric element. At present, a voltage of 40 V or less is considered appropriate due to the restrictions on the cost of parts around the drive circuit, and a laminated piezoelectric element having a thickness of 40 μm or less is used. In other words, increasing electric field strength is approaching its limit at present.

In the case of a ceramic material, which restricts material processing, the bending strength is used. The transverse rupture strength decreases when a metal material is used for the internal electrodes in the laminated piezoelectric element. Therefore, the use of a laminated element naturally imposes restrictions on processing. In the case of application to an ink-jet head, 90 heads per inch (90
dpi). In recent years, the demand for higher printing speed has made it necessary to improve the degree of integration. 300
In the design of dpi, one head is manufactured at a pitch of 85 μm,
The length of 85 μm is realized by the actuator drive unit having a length of 40 μm and the element separation space of 45 μm. Further, in the design of the 40 μm drive unit, it can be implemented with a single layer without using a laminated piezoelectric element, which is preferable from the viewpoint of improving bending strength.

(Example 1) Lead oxide, lanthanum oxide, zirconium oxide and titanium oxide were

[0024]

(Equation 3)

0.065 ≦ x <0.10, 0.60 <y <0.80, 0.8
It was weighed corresponding to the stoichiometric composition where 40>z> 0.20. Lead oxide makes up 5% of its stoichiometric excess. Various oxides were treated with a wet ball mill (using zirconia balls) using ethanol.
Pulverize and mix for time. After drying, the mixed powder is molded and 8
A two-stage calcination at 50 ° C. for 8 hours, 950 ° C. for 8 hours, and a treatment for 48 hours under the ball mill conditions described above, followed by drying to obtain a calcined PLZT powder. After adding 0.5 wt% of polyvinyl alcohol to the powder and granulating, the mixture was molded and subjected to main firing 1 at 1250 ° C. for 8 hours.
Main firing 2 is performed at 0 ° C. for 12 to 36 hours to obtain a PLZT ceramic. FIG. 4 shows the results showing the most preferable characteristics of the ceramics thus obtained. Residual strain,
It shows characteristics without virgin distortion, and the proportionality of the amount of distortion to electric field strength (corresponding to the piezoelectric constant) is between 0 and 7 kV / cm.
₃₃ = 1430 pm / V. D ₃₁ is -715p
m / V, which is 2.4 times that of conventional piezoelectric ceramics. FIG. 5 shows the Curie point measurement results. The Curie point of this material exists at about 80 ° C., which is sufficiently higher than room temperature, and reaches a humidity at which there is no effect under the actuator driving environment.

Example 2 A composition range showing the same characteristics as in Example 1 was examined by changing various compositions. Table 1 shows the results. Table 2 shows the effect of adding Ba and Sr in the PLZT (x / 70/30) series.

[0027]

[Table 1]

[0028]

[Table 2]

From the results shown in Table 1, the preferred composition range of the present invention is 0.07 <x ≦ 0.095, 0.60 <y <0.80, 0.8.
40>z> 0.20. In addition, when partially substituting strontium having an ionic radius slightly smaller than that of the lead ion, it exhibits characteristics even in the range where the lanthanum concentration decreases, while partial substitution with barium having a slightly larger ionic radius shows the characteristics even in the range where the lanthanum concentration increases. , Exhibit compatible properties.
It is presumed that these techniques for controlling the structure and stabilizing the properties of ceramics based on the ionic radius are also effective for other metal elements such as the calcium elements other than strontium and barium mentioned above. From the results in Table 2, the composition ranges in consideration of the effect of the added elements are 0.065 ≦ x <0.10, 0.60 <y <0.80, and 0.85.
40>z> 0.20.

Example 3 PLZT (9/65/35)
Various samples having different relative densities were prepared by changing the firing conditions according to the composition. The firing conditions are usually sintering (sample A), two-step sintering (B), hot press firing (C), and HIP (Hot Is
ostatic Press) firing (D). In particular, in the HIP firing, the atmosphere is Ar + oxygen, the oxygen concentration is 2 to 20%, the final ultimate temperature is 950 to 1300 ° C., and the final ultimate pressure is 30 to 150 M.
A sample having a relative density of 100% was obtained in the range of Pa and a temperature rising / falling rate of 200 ° C./h. Table 3 shows the relationship between the relative density and the characteristics of each sample.

[0031]

[Table 3]

As described above, the characteristics are improved as the relative density increases. From the viewpoint of productivity, hot pressing and HIP sintering are more complicated and less preferable than ordinary sintering methods in which other sintering pressures are not controlled, but can sufficiently respond to required specifications. In addition, it can be said that the two-stage firing has no restriction on the apparatus and can easily obtain a high sintered body.
FIG. 6 shows the electric field induced strain characteristics of the HIP baked product of PLZT (9/65/35). The value in Table 3 above is the electric field strength of 7 kV.
/ Cm is the value extrapolated linearly from the distortion at the time of / cm.

Example 4 A three-point bending fracture test was performed to measure the bending strength of ceramics. Number of samples 10
The bending strength was calculated from the points and Weibull plot. The samples were subjected to various calcinations shown in Example 3 and the calcination temperature were changed, and were submitted for evaluation. On the other hand, in the aspect processing, the sintered sample is mirror-polished on both sides, and the sample thickness is 1.0 mm 20 m.
After finishing to a sample shape of m square, it was processed by a dicer. The cutting interval is fixed at 280 μm, the short side length of the ceramic strip is fixed at 150 μm (gap width 130 μm), and the long side length is changed in a range of 1.5 to 15 mm (0.5 mm steps). This is an aspect ratio of 10-10
It corresponds to 0. Twenty comb-shaped strips are cut out for various aspect ratios, and the evaluation 1 counts the number of defect-free after cutting, and the evaluation 2 counts the number of defect-free after a post-process described later. Table 4 shows the results. In addition, the measurement was performed with the following dimensions as a narrow pitch sample aiming at high integration. That is, the cutting interval is 84.7 μm, and the short side length of the ceramic strip is 40 μm.
m (gap width 44.7 μm) and the long side length 40
It is varied in the range of 0-4000 μm (400 μm steps). This corresponds to an aspect ratio of 10-100. Twenty comb-shaped strips are cut out for various aspect ratios, and the evaluation 1 counts the number of defect-free after cutting, and the evaluation 2 counts the number of defect-free after a post-process described later. Table 5 shows the results
Shown in

[0034]

[Table 4]

[0035]

[Table 5]

As the bending strength increases, the workable aspect ratio increases. In particular, the sample with the highest bending strength subjected to the HIP treatment had all strips free of defects until cutting, which suggests that it can be manufactured with 100% accuracy by optimizing the working conditions in the post-process. are doing.

Example 5 The particle size of the HIP sample and the two-stage fired sample was measured with an electron microscope, and the particle size of the ceramic structure was determined (FIGS. 7 and 8). In the case of HIP sintering, the particles consist of uniform particles of about 2 μm, while in the case of two-step sintering, the particles consist of uneven and large particles from 5 μm to a maximum of 8 μm. The fracture strength of a polycrystal such as ceramics is determined by the latter among crystal grain strength and crystal grain boundary strength. The structure of each sample described in Table 4 was observed, and the results are shown in Table 6. For the measurement of the average particle size, draw a straight line at random from the electron micrograph,
It was calculated from the size of the particles intersecting the straight line.

[0038]

[Table 6]

It is not preferable to use particles having a size exceeding 5 μm.

(Embodiment 6) FIG. 3 schematically shows the ceramics of the present invention and an ink jet head in which an ink jet head required portion is arranged in an actuator portion subjected to an aspect process. In FIG. 3, 1 is a PLZT ceramic subjected to high aspect processing, 2 is a housing, 3 is a vibration plate, 4 is an ink liquid chamber, 5 is an ink supply channel, 6 is a fluid resistance part, and 7 is a nozzle plate. . These parts are laminated / joined by a known joining technique, and an ink jet head is completed. It should be noted that the strip-shaped PLZT processing element is arranged in the direction toward the back of the paper. As mentioned earlier, strip processing when using conventional piezoelectric ceramics,
Piezoelectric constant d ₃₁ = -300 pm / V, deformation basic length 6.0 m
m (aspect ratio = 40). At this time -1.8μ
m displacement is obtained.

The PLZT of the present invention (8.4 / 70/30)
D ₃₃ of the HIP processing products 1610pm / V, d ₃₁ = -8
05 pm / V (when driven at 7 kV / cm), and to obtain the same displacement, drive at 28 V (7 kV / c at an electrode width of 40 μm).
m), 2.24 mm may be taken as the deformation basic length. Further, in order to obtain a further huge displacement, it is possible to perform processing with 100 samples of aspect processing, and the displacement amount at this time reached 3.22 μm.

When the limitation of the driving voltage is not considered,
The above-mentioned displacement is not limited to this value, and there is no problem even if this PLZT ceramic is used for the laminated element. In addition, a conventional piezoelectric body does not exhibit an actuator function unless it is subjected to polarization processing, whereas the present PLZT system shows its function sufficiently without performing such processing. This is very effective because the polarization process in the device manufacturing process can be omitted.

[0043]

Since the present invention is configured as described above, the following effects can be obtained. According to the first aspect of the present invention, since the lead-based dielectric ceramic has no virgin strain and no residual strain, the amount of displacement or strain generated when an electric field is applied is larger than that of a conventional piezoelectric ceramic, and the Curie point is low. Since it is high, it is suitable for, for example, an actuator.

According to a second aspect of the present invention, in the lead-based dielectric ceramic, the main composition is represented by the formula

[0045]

(Equation 4)

Where x, y, and z are 0.065 ≦ x <0.10, 0.60 <y <0.80, and
Since 40>z> 0.20, the amount of displacement or strain generated when an electric field is applied is large, and the Curie point is sufficiently higher than room temperature. Therefore, it is suitable for an actuator such as an inkjet head of an inkjet printer. . Also, PZL
Since T is a main component and Ba and Sr are partially replaced by lead as a sub-constituting element, the composition range can be widened and the characteristics can be stabilized.

According to the third aspect of the present invention, by increasing the relative density of the ceramics to 98% or more to improve the density of the ceramics, the amount of distortion generated when an electric field is applied can be further improved.

According to the fourth aspect of the present invention, since the bending strength of the ceramic is 80 Mpa or more, the degree of freedom in designing various shapes required for the actuator element can be improved.

According to the fifth aspect of the present invention, the degree of freedom in design for fine processing can be improved by improving the ceramic structure and reducing the size of the ceramic particles to 5 μm or less.

The invention according to claim 6 uses a lead-based dielectric ceramic having a large piezoelectric constant and a high Curie point as an actuator for an ink-jet head or the like of an ink-jet printer as compared with a conventional piezoelectric ceramic. , Higher density, lower drive voltage, etc. can be realized.

[Brief description of the drawings]

FIG. 1 Lead-based dielectric ceramic PLZT (6.0 /
80/20) and PLZT (7.0 / 80/20) showing electric-field-induced strain characteristics.

FIG. 2 Lead-based dielectric ceramics PLZT (7.5 /
FIG. 75 is a diagram showing a strain response characteristic of the PLZT (7.0 / 80/20) to the first driving electric field.

FIG. 3 is a view schematically showing an inkjet head using a lead-based dielectric ceramic of the present invention for an actuator section.

FIG. 4 is a view showing an electric field-induced strain characteristic of the lead-based dielectric ceramic of the present invention.

FIG. 5 is a diagram showing the Curie point of the lead-based dielectric ceramic of the present invention.

FIG. 6 is a lead-based dielectric ceramic PLZT of the present invention.
It is a figure which shows the electric field induced distortion characteristic of the (9/65/35) HIP fired article.

FIG. 7 is an electron micrograph showing a ceramic structure of a HIP fired sample.

FIG. 8 is an electron micrograph showing a ceramic structure of a two-stage fired sample.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... PZLT ceramics, 2 ... housing, 3 ... diaphragm, 4
... Ink liquid chamber, 5 ... Ink supply flow path, 6 ... Fluid resistance section,
7 ... Nozzle plate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 41/09

Claims (6)

[Claims] 1. A lead-based dielectric ceramic which generates electric-field-induced strain, wherein the lead-free dielectric ceramic has no virgin strain and no residual strain, and has a Curie point higher than an actual use temperature. 2. The lead-based dielectric ceramic according to claim 1, wherein the main composition is represented by the following formula: 0.065 ≦ x <0.10, 0.60 <y <0.80, 0.1.
40>z> 0.20, and Ba, S
Lead-based dielectric ceramics in which r is partially replaced by lead. 3. A lead-based dielectric ceramic, wherein the relative density of the ceramic according to claim 2 is 98% or more. 4. A lead-based dielectric ceramic having a flexural strength of 80 Mpa or more according to claim 1. 5. A lead-based dielectric ceramic according to claim 1, wherein the ceramic particle size of the ceramic according to claim 1 is 5 μm or less. 6. The lead-based dielectric ceramic according to claim 1, which is used as an electromechanical transducer,
An actuator formed by arranging a diaphragm, a liquid chamber, a liquid chamber flow path, and a nozzle after processing into a desired shape.