KR101980873B1 - Piezoelectric ceramic composition and piezoelectric ceramic element using the same - Google Patents

Abstract

The present invention provides a piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1), wherein the piezoelectric ceramic composition has a rhombohedral structure and a tetragonal structure. The present invention relates to a piezoelectric ceramic composition and a piezoelectric ceramic device using the same, wherein the ratio of the phase fraction between the rhombohedral structure and the tetragonal structure is 10:90 to 18:82.

Description

Piezoelectric ceramic composition and piezoelectric ceramic device using the same {PIEZOELECTRIC CERAMIC COMPOSITION AND PIEZOELECTRIC CERAMIC ELEMENT USING THE SAME}

The present invention relates to a piezoelectric ceramic composition and a piezoelectric ceramic device using the same.

A representative piezoceramic composition which has been widely used to date is a lead (Pb) -containing composition (PZT-based piezoelectric ceramic composition) based on Pb (Zr, Ti) O ₃ . Due to the recent increase in international social concern about environmental pollution of lead, the harmfulness of the regulation legislation on the use of lead in electronics and electrical equipment (EU: RoHS, USA: TSCA, China: China RoHS) has become effective. The use of materials has been restricted and the collection and recycling of waste electrical and electronic products is mandatory.

Accordingly, studies on environmentally friendly lead-free piezoelectric ceramic compositions for replacing the existing PZT piezoelectric ceramic compositions have been actively conducted, among which lead (Pb) -free compositions (KNN-based) based on (K, Na) NbO ₃ are used. Piezoelectric ceramic composition) exhibits high Curie temperature (250 ~ 420 ℃) and excellent piezoelectric properties ( d ₃₃ = 150 ~ 500pC / N), so it is an eco-friendly non-lead piezoelectric ceramic to replace PZT piezoelectric ceramic composition. It is a situation attracting great attention as a candidate material for the composition.

KNN-based piezoelectric ceramic composition has a polymorphic phase boundary (phase structure) changes with temperature, by doping a variety of materials to pure KNN-based piezoelectric ceramic composition, Orthorhombic, tetragonal ( In order to further improve piezoelectric properties by forming a phase boundary in which two or more phase structures of tetragonal) and rhombohedral are mixed.

However, there have been no examples of studying the maximum piezoelectric properties by controlling the phase fraction of each phase structure in the phase boundary of the KNN-based piezoelectric ceramic composition.

Korea Patent Publication No. 10-2015-0037483 (2015. 04. 08.)

The present invention provides a piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1), wherein the piezoelectric ceramic composition has a rhombohedral structure and a tetragonal structure. It is to provide a piezoelectric ceramic composition and the like having a phase boundary including, the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure is 10:90 to 18:82.

However, the technical problem to be achieved by the present invention is not limited to the above-mentioned problem, another task that is not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1), wherein the piezoelectric ceramic composition has a rhombohedral structure and a tetragonal structure. It has a phase boundary including, the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure provides a piezoelectric ceramic composition, characterized in that 10:90 to 18:82.

In one embodiment of the present invention, a piezoelectric ceramic device using the piezoelectric ceramic composition is provided.

The piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1) according to the present invention has a phase boundary including a rhombohedral structure and a tetragonal structure, The ratio of the phase ratio of the rhombohedral structure and the tetragonal structure is 10:90 to 18:82, the piezoelectric ceramic composition has a high piezoelectric temperature, but has a maximum piezoelectric characteristic ( d ₃₃ ) Bars may be usefully used as piezoelectric ceramic devices of various forms. In this case, since the piezoelectric ceramic element does not contain lead, it has an advantage of preventing environmental pollution due to lead.

1 shows (a) XRD (44-47 °) pattern of a piezoelectric ceramic composition (x1 = 0, 0.01, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.06, 0.07) prepared according to Example 1 As a result of analysis, (b) dielectric constant ( ε _r ) measurement according to -100 ~ 200 ℃ temperature, (c) Rhombohedral (R) structure at room temperature (25 ℃) by XRD Rietveld refinement method, This graph shows the results of the calculation of the phase ratio of the Orthorhombic (O) structure and the tetragonal (T) structure and the evaluation result of (d) the piezoelectric constant ( d ₃₃ ).
2 is (a) XRD (44-47 °) of the piezoelectric ceramic composition (x2 = 0.03, 0.035, 0.04, 0.045, 0.05, y2 = 0, 0.005, 0.01, 0.015, 0.02, 0.03) prepared according to Example 2; ) Pattern analysis results, (b) Dielectric constant ( ε _r ) measurement results according to the temperature of -100 ~ 200 ℃, (c) Rhombohedral (R) structure at room temperature (25 ℃) by XRD Rietveld refinement method, everywhere The graph shows the results of the calculation of the percentage of the Orthorhombic (O) structure and the Tetragonal (T) structure and the evaluation results of (d) the piezoelectric constant ( d ₃₃ ).
Figure 3 is a (a) XRD (44 ~ 47 °) pattern analysis of the piezoelectric ceramic composition (y3 = 0, 0.005, 0.01, 0.015, 0.02) prepared according to Example 3, (b) -100 ~ 200 ℃ temperature Dielectric constant ( ε _r ) measurement results according to (c), (c) Rhombohedral (R) structure, Orthorhombic (O) structure and tetragonal (Tetragonal; T at room temperature (25 ℃) by XRD Rietveld refinement method ) Is a graph showing the results of the calculation of the phase ratio of the structure and (d) the piezoelectric constant ( d ₃₃ ).

The inventors of the present invention, while studying the correlation between the phase fraction and the maximum piezoelectric properties of each phase structure in the phase boundary of the KNN-based piezoelectric ceramic composition, in the phase boundary of the Rhombohedral-Tegonal structure When the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure is 10:90 to 18:82, it was confirmed that the maximum piezoelectric characteristic ( d ₃₃ ) was shown, and the present invention was completed.

As used herein, the term “piezoelectric” refers to a function of mutually converting mechanical energy and electrical energy through a piezoelectric medium, and refers to an effect of generating electricity when pressure or vibration (mechanical energy) is applied. Indicators indicating such piezoelectric performance include piezoelectric constants d ₃₃ and d ₃₁ . In this case, the piezoelectric constant refers to the degree of displacement when the electric field (V / m) is applied or vice versa, the larger the piezoelectric constant has the advantage that the micro displacement control is possible.

Hereinafter, the present invention will be described in detail.

The present invention provides a piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1), wherein the piezoelectric ceramic composition has a rhombohedral structure and a tetragonal structure. It has a phase boundary including, the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure provides a piezoelectric ceramic composition, characterized in that 10:90 to 18:82.

First, the piezoelectric ceramic composition according to the present invention contains (K _a Na _(1-a) ) NbO ₃ (0 <a <1) as a basis, also referred to as a KNN-based piezoelectric ceramic composition. The KNN-based piezoelectric ceramic composition exhibits a high Curie temperature (250-420 ° C.) and excellent piezoelectric properties ( d ₃₃ = 150-500 pC / N) at the same time, thereby replacing the PZT piezoelectric ceramic composition with non-lead piezoelectric ceramics. It can be seen as a ceramic composition. Therefore, there is an advantage that can prevent the environmental pollution due to lead.

In addition to the above piezoelectric ceramic composition _{(K a Na (1-a} )) NbO 3 (0 <a <1), Bi 0 .5 (Na b1 K b2 Li (1-b1-b2)) 0.5 ZrO 3 (0≤ b1 ≦ 1, 0 ≦ b2 ≦ 1) may be further included. _{Bi 0 .5 (Na b1 K b2} Li (1-b1-b2)) 0.5 ZrO 3 (0≤b1≤1, 0≤b2≤1) a predetermined amount or more, preferably 4.5 mol% to 5 mol% doping In this case, the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure can be maintained within the range of 10:90 to 18:82 (specifically, 16:84 to 18:82), and thus the maximum piezoelectric characteristic ( d ₃₃ ). Can be seen.

Further, the piezoelectric ceramic composition _{(K a Na (1-a} )) NbO 3 (0 <a <1) and _{Bi 0 .5 (Na b1 K b2} Li (1-b1-b2)) 0.5 ZrO 3 (0 In addition to ≦ b1 ≦ 1 and 0 ≦ b2 ≦ 1), BiScO ₃ may be further included. Doping Bi _0.5 (Na _b1 K _b2 Li _(1-b1-b2) ) _0.5 ZrO ₃ (0 ≦ _b1 ≦ 1, 0 ≦ _b2 ≦ 1) to at least a certain amount, preferably 3 to 4 mol%, When BiScO ₃ is doped in a predetermined amount or more, preferably 0.5 mol% to 1 mol%, the ratio of the phase fractions of the rhombohedral structure and the tetragonal structure is in the range of 10:90 to 18:82 (specifically, 14:86 To 16:84, thereby exhibiting a maximum piezoelectric characteristic d ₃₃ .

Further, the piezoelectric ceramic composition _{(K a Na (1-a} )) NbO 3 (0 <a <1) and _{Bi 0 .5 (Na b1 K b2} Li (1-b1-b2)) 0.5 ZrO 3 (0 In addition to ≦ b1 ≦ 1 and 0 ≦ b2 ≦ 1), (Bi _c Na _(1-c) ) TiO ₃ (0 ≦ _c ≦ 1) may be further included. Bi _{0 .5} (K _{b2 b1} Na Li _{(1-b2-b1)) 0.5} ZrO ₃ (0≤b1≤1, 0≤b2≤1) a predetermined amount or more, and doped with about 3 mol%, Bi _{0 .5} (Na _b1 K _b2 Li _(1-b1-b2) ) When doping _0.5 ZrO ₃ (0 ≦ _b1 ≦ 1, 0 ≦ _b2 ≦ 1) above a certain amount, preferably 1.5 mol% to 2 mol%, It is possible to maintain the ratio of the phase ratios of the crystalline structure and the tetragonal structure within the range of 10:90 to 18:82 (specifically, 11:89 to 15:85), thereby exhibiting the maximum piezoelectric characteristic d ₃₃ . .

Specifically, the piezoelectric ceramic composition may have at least one composition selected from the group consisting of the following Chemical Formulas 1 to 3:

[Formula 1]

_{(1-x1) (K a} Na (1-a)) NbO 3 -x1Bi 0 .5 (Na b1 K b2 Li (1-b1-b2)) 0.5 ZrO 3 (0.04 <x1 <0.06, 0 <a <1, 0 ≦ b1 ≦ 1, 0 ≦ b2 ≦ 1),

[Formula 2]

(1-x2-y2) ( K a Na (1-a)) NbO 3 -x2Bi 0 .5 (Na b1 K b2 Li (1-b1-b2)) 0.5 ZrO 3 -y2BiScO 3 (0.025 <x2 ≦ 0.05, 0 <y2 <0.015, 0 <a <1, 0 ≦ b1 ≦ 1, 0 ≦ b2 ≦ 1),

[Formula 3]

_{(0.97-y3) (K a} Na (1-a)) NbO 3 -0.03Bi 0 .5 (Na b1 K b2 Li (1-b1-b2)) 0.5 ZrO 3 -y3 (Bi c Na (1-c ₎ ) TiO ₃ (0.010 <y3 <0.025, 0 <a <1, 0 ≦ b1 ≦ 1, 0 ≦ b2 ≦ 1 and 0 ≦ c ≦ 1).

In the phase boundary, the phase structure may depend on the temperature. Therefore, as the phase boundary rhombohedral-square tetragonal structure, the ratio of the phase fraction of the rhombohedral structure and the tetragonal structure is 10:90 to 18:82, it can be confirmed at 10 ℃ to 50 ℃, 20 It is preferable to confirm at 40 to 40 degreeC, and it is preferable to confirm at normal temperature 25, but it is not limited to this.

The phase boundary is characterized in that it does not include a tetragonal structure. At this time, when the tetragonal structure is included, the piezoelectric characteristics are deteriorated. Specifically, in order to implement the phase boundary that does not contain an orthorhombic _{structure, (K a Na (1-} a)) NbO 3 (0 <a <1), Bi 0 .5 (Na b1 K b2 Li (1- _b1-b2) ) Increase the doping amount of _0.5 ZrO ₃ (0 ≦ _b1 ≦ 1, 0 ≦ _b2 ≦ 1), or increase BiScO ₃ or (Bi _c Na _(1-c) ) TiO ₃ (0 ≦ _c ≦ 1) It is necessary to increase the doping amount.

The piezoelectric constant d ₃₃ of the piezoelectric ceramic composition may be 200 pC / N to 500 pC / N, and preferably 300 pC / N to 500 pC / N, but is not limited thereto.

In addition, the present invention provides a piezoelectric ceramic device using the piezoelectric ceramic composition.

The piezoelectric ceramic device according to the present invention is manufactured by using the piezoelectric ceramic composition, and the details of the "piezoelectric ceramic composition" are as described above, and thus redundant description will be omitted.

The piezoelectric ceramic element has a maximum piezoelectric characteristic bar, a shock sensor; Acceleration sensor; Ultrasonic sensors; Stacked piezoelectric actuators; Piezoelectric transformers; And it can be manufactured with a high-reliability piezoelectric component such as an ultrasonic vibrator or an ignition element, and at this time, it does not contain lead, there is an advantage that can prevent the environmental pollution due to lead.

Accordingly, the piezoelectric ceramic composition including (K _a Na _(1-a) ) NbO ₃ (0 <a <1) according to the present invention may be a phase boundary system including a rhombohedral structure and a tetragonal structure. The ratio of the phase fraction of the rhombohedral structure and the tetragonal structure is 10:90 to 18:82, wherein the piezoelectric ceramic composition has a high Curie temperature and has a maximum piezoelectric property ( d ₃₃ ). It can be usefully used as a piezoelectric ceramic device of various forms. In this case, since the piezoelectric ceramic element does not contain lead, it has an advantage of preventing environmental pollution due to lead.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the following examples.

[ Example ]

Example  One

_{(K 0.48 Na 0.52) NbO 3} ( hereinafter 'KNN' term) to _{Bi 0 .5 (Na 0 .7 K} 0. 2 Li 0. 1) 0.5 ZrO 3 ( hereinafter referred to as 'BNKLZ') 0 The piezoelectric ceramic composition [(1-x1) KNN-x1BNKLZ] was prepared by doping to ˜7 mol%.

Figure 1 shows the results of (a) XRD (44 ~ 47 °) pattern analysis of the piezoelectric ceramic composition prepared according to Example 1, (b) measurement of the dielectric constant ( ε _r ) according to the temperature of -100 ~ 200 ℃, (c ) Calculation results of phase fractions of Rhombohedral (R), Orthorhombic (O) and Tetragonal (T) structures at room temperature (25 ℃) by XRD Rietveld refinement method and (d) Piezoelectric constant ( d ₃₃ ) A graph showing the evaluation results.

As shown in Figure 1 (a) and (b), it is confirmed that the XRD (44 ~ 47 °) pattern changes and the position of the peak corresponding to T _RO and T _OT changes as the doping amount of BNKLZ increases. Through this, when analyzing the phase structure of the piezoelectric ceramic composition prepared according to Example 1, when the BNKLZ is doped or doped small (0 mol%, 1 mol%) while maintaining the O structure, the doping amount of the BNKLZ increases According to (2 mol%, 2.5 mol%, 3 mol%, 3.5 mol%, 4 mol%) to R-0-T structure, and then as the doping amount of BNKLZ further increased (4.5 mol%, 5 mol%, 6 mol%, 7 mol%) is confirmed to change back to the RT structure. However, even if the upper boundary of the same structure, the position of the peak corresponding to the XRD (44 ~ 47 °) pattern and T _RO and T _OT is confirmed to be slightly different, which is the angle of the upper boundary even if the upper boundary of the same structure This is because the ratio of the percentage of the structure to the structure is different.

As shown in FIG. 1 (c), as the doping amount of BNKLZ increases, the O structure decreases and eventually disappears, and it is confirmed that an R-T structure phase boundary is formed. In addition, after the upper boundary of the R-T structure is formed, it is confirmed that the phase fraction of the R structure gradually increases with respect to the total upper boundary.

As shown in FIG. 1 (d), as the doping amount of BNKLZ increases, the piezoelectric constant d ₃₃ increases and decreases again. Specifically, when the doping amount of BNKLZ is 4.5-5 mol% (that is, when the ratio of the percentage of R structure and T structure is 16.3: 83.7-17.6: 82.4), the piezoelectric constant d ₃₃ is confirmed to be the maximum. .

Example  2

_{(K 0.48 Na 0.52) Bi 0} .5 to NbO ₃ (hereinafter referred to _{as, 'KNN') (Na 0} .7 K 0. 2 Li 0. 1) 0.5 ZrO 3 ( hereinafter referred to as 'BNKLZ') 3 the After doping to ˜5 mol%, BiScO ₃ (hereinafter referred to as 'BS') was dope to 0 to 3 mol% to prepare a piezoelectric ceramic composition [(1-x2-y2) KNN-x2BNKLZ-y2BS].

Figure 2 shows the results of (a) XRD (44 ~ 47 °) pattern analysis of the piezoelectric ceramic composition prepared according to Example 2, (b) measurement of the dielectric constant ( ε _r ) according to the temperature of -100 ~ 200 ℃, (c ) Calculation results of phase fractions of Rhombohedral (R), Orthorhombic (O) and Tetragonal (T) structures at room temperature (25 ℃) by XRD Rietveld refinement method and (d) Piezoelectric constant ( d ₃₃ ) A graph showing the evaluation results.

As shown in Fig. 2 (a) and (b), it is confirmed that as the doping amount of the BS increases, the XRD (44-47 °) pattern changes and the positions of peaks corresponding to T _RO and T _OT change. Through this, when analyzing the phase structure of the piezoelectric ceramic composition prepared according to Example 2, when the BNKLZ doped 3 mol%, 3.5 mol% or 4 mol%, BS is not doped or small doped R-0- While maintaining the T structure, it is confirmed that the change to the RT structure as the doping amount of the BS increases. On the other hand, when BNKLZ is doped 4.5 mol% or 5 mol%, it is confirmed to form a phase boundary of the RT structure regardless of the amount of BS doping.

In addition, it is confirmed that as the amount of BNKLZ and BS doping increases, T _{R- O} gradually increases and T _OT gradually decreases. Specifically, when the T _OT decreases below 127 ° C. while the T _{R- O} increases above -80 ° C., a phase boundary of the ROT structure is formed at room temperature. As the BNKLZ and BS doping amounts are further increased, the peaks corresponding to T _RO and T _OT merge into one peak near room temperature, thereby forming a phase boundary of the RT structure at room temperature. However, even if they have the same structure, the position of the peaks corresponding to the XRD (44 to 47 °) pattern and the T _RO and T _O-T is slightly different. This is because the ratio of the percentage of phases of each structure to be formed is different.

As shown in FIG. 2 (c), as the doping amounts of BNKLZ and BS increase, the O structure decreases and eventually disappears, and it is confirmed that an R-T structure phase boundary is formed. In addition, after the upper boundary of the R-T structure is formed, it is confirmed that the phase fraction of the R structure gradually increases with respect to the total upper boundary.

As shown in FIG. 2 (d), when BNKLZ is doped with 3 mol%, 3.5 mol% or 4 mol%, the piezoelectric constant d ₃₃ increases and decreases again as the doping amount of the BS increases. It is confirmed. Specifically, when the doping amount of BS is 0.5-1 mol% (that is, when the ratio of the phase ratio of the R structure and the T structure is 14.4: 85.6-15.8: 84.2), it is confirmed that the piezoelectric constant d ₃₃ is the maximum. .

Example  3

_{(K 0.48 Na 0.52) Bi 0} .5 to NbO ₃ (hereinafter referred to _{as, 'KNN') (Na 0} .7 K 0. 2 Li 0. 1) 0.5 ZrO 3 ( hereinafter referred to as 'BNKLZ') 3 the And then doped with (Bi _0.5 Na _0.5 ) TiO ₃ (hereinafter referred to as 'BNT') to 0-2 mol% to form a piezoelectric ceramic composition [(0.97-y3) KNN-0.03BNKLZ-y3BNT]. Prepared.

Figure 3 is a (a) XRD (44 ~ 47 °) pattern analysis results of the piezoelectric ceramic composition prepared according to Example 3, (b) dielectric constant ( ε _r ) measurement results according to the temperature of -100 ~ 200 ℃, (c ) Calculation results of phase fractions of Rhombohedral (R), Orthorhombic (O) and Tetragonal (T) structures at room temperature (25 ℃) by XRD Rietveld refinement method and (d) Piezoelectric constant ( d ₃₃ ) A graph showing the evaluation results.

As shown in Figure 3 (a) and (b), it is confirmed that the XRD (44 ~ 47 °) pattern changes and the position of the peak corresponding to T _RO and T _OT changes as the doping amount of BNT increases. When BNT is not doped or lightly doped (0 mol%, 0.5 mol%, 1 mol%), the R-0-T structure is maintained, and as the doping amount of BNT increases (1.5 mol%, 2 mol%), RT structure It is confirmed that the change. However, even if the upper boundary of the same structure, the position of the peak corresponding to the XRD (44 ~ 47 °) pattern and T _RO and T _OT is confirmed to be slightly different, which is the angle of the upper boundary even if the upper boundary of the same structure This is because the ratio of the percentage of the structure to the structure is different.

As shown in FIG. 3 (c), as the doping amount of BNT increases, the O structure decreases and eventually disappears, and it is confirmed that an R-T structure phase boundary is formed. In addition, after the upper boundary of the R-T structure is formed, it is confirmed that the phase fraction of the T structure gradually increases with respect to the total upper boundary.

As shown in FIG. 3 (d), as the doping amount of BNT increases, the piezoelectric constant d ₃₃ increases and decreases again. Specifically, when the doping amount of BNT is 1.5 to 2 mol% (that is, when the ratio of the phase ratio of the R structure and the T structure is 11.3: 88.7 to 14.7: 85.3), the piezoelectric constant d ₃₃ is confirmed to be the maximum. .

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (9)

In the piezoelectric ceramic composition comprising (K _a Na _(1-a) ) NbO ₃ (0 <a <1),
The piezoelectric ceramic composition has at least one composition selected from the group consisting of the following Chemical Formulas 1 to 3,
Checking the piezoelectric ceramic composition at 10 ℃ to 50 ℃, as a result, including a rhombohedral (Rhombohedral) structure and a tetragonal (Tetragonal) structure, and has a phase boundary that does not include an Orthorhombic structure, the rhombohedral structure And a piezoelectric constant (d ₃₃ ) of 200 pC / N to 500 pC / N, wherein the ratio of the phase fraction of the tetragonal structure is 10:90 to 18:82.
[Formula 1]
(1-x1) (K _a Na _(1-a) ) NbO ₃ -x1Bi _0.5 (Na _b1 K _b2 Li _(1-b1-b2) ) _0.5 ZrO ₃ (0.045 ≦ x1 ≦ 0.05, 0 <a <1, 0≤b1≤1, 0≤b2≤1),
[Formula 2]
(1-x2-y2) (K _a Na _(1-a) ) NbO ₃ -x2Bi _0.5 (Na _b1 K _b2 Li _(1-b1-b2) ) _0.5 ZrO ₃ -y2BiScO ₃ (0.03≤x2≤0.04, 0.005 ≤y2≤0.01, 0 <a <1, 0≤b1≤1, 0≤b2≤1),
[Formula 3]
(0.97-y 3) (K _a Na _(1-a) ) NbO ₃ -0.03Bi _0.5 (Na _b1 K _b2 Li _(1-b1-b2) ) 0.5ZrO ₃ -y3 (Bi _c Na _(1-c) ) TiO ₃ (0.015 ≦ y3 ≦ 0.02, 0 <a <1, 0 ≦ b1 ≦ 1, 0 ≦ b2 ≦ 1 and 0 ≦ c ≦ 1).
delete delete delete delete delete The method of claim 1,
The piezoelectric ceramic composition is a piezoelectric ceramic composition, characterized in that non-lead-based.
delete A piezoelectric ceramic device using the piezoelectric ceramic composition according to claim 1.

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