Piezoelectric composition, piezoelectric device, laminated actuator, method for producing piezoelectric composition, and method for producing laminated actuator

Abstract

To provide a piezoelectric composition which can be fired at a low temperature.SOLUTION: A piezoelectric composition according to an aspect of the present disclosure is a piezoelectric composition containing a composition represented by the following composition formula A as a main component, and containing jmol% of a manganese element and kmol% of a silver element with respect to 1 mol of the main component. Composition formula A: {(NaaKb) 1-c-dBac (Bi0.5Li0.5) d} e (Nb1-f-gSbfTag) 1-h-iZrhTiiO3. Here, 0.3<a<0.7, 0.3<b<0.7, 0.03<c<0.09, 0<d<0.05, 0.9<e<1.1, 0<f<0.04, 0.02<g<0.08, 0.03<h<0.09, 0<i<0.05, 0.5<j<5, and 0<k<5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a piezoelectric composition, a piezoelectric device, a laminated actuator, a method for manufacturing a piezoelectric composition, and a method for manufacturing a laminated actuator. [Background technology]

[0002] Piezoelectric compositions are used in a variety of piezoelectric devices, such as various sensors, ultrasonic vibrators, piezoelectric transformers, piezoelectric actuators, and piezoelectric speakers.

[0003] Known piezoelectric compositions include perovskite oxides such as lead zirconate titanate (PZT), barium titanate (BaTiO3), and potassium niobate (KNbO3). Among these, lead-free barium titanate (BaTiO3) and potassium niobate (KNbO3) are attracting attention due to environmental concerns, such as the lack of lead pollution.

[0004] Patent Document 1 discloses a technology relating to an environmentally friendly piezoelectric composition that is mainly composed of (Na,Ka)NbO3, forms the same rhombohedral-tetragonal phase boundary as PZT, and has excellent thermal conductivity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2008 / 143160 Summary of the Invention [Problem to be solved by the invention]

[0006] The piezoelectric composition disclosed in Patent Document 1 is lead-free and has good piezoelectric properties because it is mainly composed of (Na,Ka)NbO3. However, the piezoelectric composition disclosed in Patent Document 1 has a problem in that the firing temperature is high when forming the piezoelectric composition.

[0007] In view of the above problems, an object of the present disclosure is to provide a piezoelectric composition, a piezoelectric device, a laminated actuator, a method for manufacturing a piezoelectric composition, and a method for manufacturing a laminated actuator, which are capable of lowering the firing temperature when forming the piezoelectric composition. [Means for solving the problem]

[0008] A piezoelectric composition according to one embodiment of the present disclosure is a piezoelectric composition that contains a composition represented by the following composition formula A as a main component, and contains j mol % of elemental manganese and kmol % of elemental silver per 1 mol of the main component. Composition formula A: {(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d} e (Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i O3 where 0.3 <a<0.7、0.3<b<0.7、0.03<c<0.09、0<d<0.05、0.9<e<1.1、0≦f<0.04、0.02<g<0.08、0.03<h<0.09、0<i<0.05、0.5<j<5、0<k<5である。

[0009] In the above-mentioned composition formula A, 0.4≦a≦0.6, 0.4≦b≦0.6, 0.04≦c≦0.08, 0.01≦d≦0.04, 0.95≦e≦1.05, 0≦f≦0.03, 0.04≦g≦0.06, 0.04≦h≦0.08, 0.01≦i≦0.04, 1≦j≦4, 0 <k<4であってもよい。

[0010] The piezoelectric constant d of the above-mentioned piezoelectric composition 33 may be greater than 400 pm / V.

[0011] The density of the above piezoelectric composition is 4.60 g / cm 3 It may be more than that.

[0012] A piezoelectric device according to one aspect of the present disclosure includes the above-described piezoelectric composition and electrodes for applying a voltage to the piezoelectric composition.

[0013] In the above-described piezoelectric device, the piezoelectric composition and a plurality of the electrodes may be stacked alternately.

[0014] A laminated actuator according to one aspect of the present disclosure includes the above-described piezoelectric composition and electrodes for applying a voltage to the piezoelectric composition, with the piezoelectric composition and a plurality of the electrodes being laminated alternately.

[0015] A method for producing a piezoelectric composition according to one embodiment of the present disclosure includes the steps of preparing a raw material powder containing a composition represented by the following composition formula A as a main component, and containing j mol % of elemental manganese and kmol % of elemental silver per 1 mol of the main component; pre-firing the raw material powder at 800°C to 950°C; pulverizing the pre-fired body obtained by the pre-firing; pressing the pulverized powder to form a compact; and firing the compact at 1000°C to 1100°C. Composition formula A: {(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d} e (Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i O3 where 0.3 <a<0.7、0.3<b<0.7、0.03<c<0.09、0<d<0.05、0.9<e<1.1、0≦f<0.04、0.02<g<0.08、0.03<h<0.09、0<i<0.05、0.5<j<5、0<k<5である。

[0016] A method for manufacturing a stacked actuator according to one aspect of the present disclosure includes the steps of: preparing a raw material powder containing a composition represented by the following composition formula A as a main component and containing j mol % of elemental manganese per 1 mol of the main component; alternately stacking the raw material powder and internal electrodes containing silver to produce a laminate; and firing the laminate at 1000°C to 1100°C, wherein in the firing step, silver is diffused from the internal electrodes so that the fired body of the raw material powder contains kmol % of elemental silver per 1 mol of the main component. Composition formula A: {(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d} e (Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i O3 where 0.3 <a<0.7、0.3<b<0.7、0.03<c<0.09、0<d<0.05、0.9<e<1.1、0≦f<0.04、0.02<g<0.08、0.03<h<0.09、0<i<0.05、0.5<j<5、0<k<5である。 [Effects of the Invention]

[0017] The present disclosure can provide a piezoelectric composition that can reduce the firing temperature when forming the piezoelectric composition, a piezoelectric device, a stacked actuator, a method for manufacturing a piezoelectric composition, and a method for manufacturing a stacked actuator. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a graph showing the temperature characteristics of the relative dielectric constant of an example and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following describes the embodiments. The piezoelectric composition according to the present disclosure is a piezoelectric composition containing, as a main component, a composition represented by the following compositional formula A, and containing j mol% of manganese element and k mol% of silver element with respect to 1 mol of the main component.

[0020] Compositional formula A: {(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d}} e (Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i O3

[0021] Here, 0.3 < a < 0.7, 0.3 < b < 0.7, 0.03 < c < 0.09, 0 < d < 0.05, 0.9 < e < 1.1, 0 ≤ f < 0.04, 0.02 < g < 0.08, 0.03 < h < 0.09, 0 < i < 0.05, 0.5 < j < 5, 0 < k < 5.

[0022] The piezoelectric composition represented by the above compositional formula A has a perovskite structure. "{(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d}} e " in the compositional formula A corresponds to the A site of the perovskite structure. Also, "(Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i " in the compositional formula A corresponds to the B site of the perovskite structure.

[0023] a is the composition ratio (molar ratio) of Na, and the range of 0.3 < a < 0.7 is preferable, and the range of 0.4 ≤ a ≤ 0.6 is more preferable.

[0024] b is the composition ratio (molar ratio) of K, and the range of 0.3 < b < 0.7 is preferred, and the range of 0.4 ≤ b ≤ 0.6 is more preferred.

[0025] c is the composition ratio (molar ratio) of Ba, and the range of 0.03 < c < 0.09 is preferred, and the range of 0.04 ≤ c ≤ 0.08 is more preferred.

[0026] d is 0.5 Li 0.5 the composition ratio (molar ratio) of, and the range of 0 < d < 0.05 is preferred, and the range of 0.01 ≤ d ≤ 0.04 is more preferred.

[0027] e is the composition ratio (molar ratio) of site A, and the range of 0.9 < e < 1.1 is preferred, and the range of 0.95 ≤ e ≤ 1.05 is more preferred.

[0028] f is the composition ratio (molar ratio) of Sb, and the range of 0 ≤ f < 0.04 is preferred, and the range of 0 ≤ f ≤ 0.03 is more preferred, and the range of 0.01 ≤ f ≤ 0.03 is even more preferred.

[0029] g is the composition ratio (molar ratio) of Ta, and the range of 0.02 < g < 0.08 is preferred, and the range of 0.04 ≤ g ≤ 0.06 is more preferred.

[0030] h is the composition ratio (molar ratio) of Zr, and the range of 0.03 < h < 0.09 is preferred, and the range of 0.04 ≤ h ≤ 0.08 is more preferred.

[0031] i is the composition ratio (molar ratio) of Ti, and the range of 0 < i < 0.05 is preferred, and the range of 0.01 ≤ i ≤ 0.04 is more preferred.

[0032] j is the content (mol%) of Mn with respect to 1 mol of the composition represented by the composition formula A, and the range of 0.5 < j < 5 is preferred, and the range of 1 ≤ j ≤ 4 is more preferred.

[0033] k is the content (mol%) of Ag with respect to 1 mol of the composition represented by the compositional formula A, and a range of 0 < k < 5 is preferable, a range of 0 < k < 4 is more preferable, and a range of 0.03 ≦ k < 4 is even more preferable.

[0034] In the piezoelectric composition according to this embodiment, by setting a to k within the above ranges, the piezoelectric properties can be improved. Specifically, in the piezoelectric composition according to this embodiment, the piezoelectric constant d of the piezoelectric composition 33 can be made greater than 400 pm / V, and characteristics at a practical level can be obtained as a piezoelectric device.

[0035] Also, in the piezoelectric composition according to this embodiment, by setting a to k within the above ranges, the density of the piezoelectric composition can be increased. Specifically, in the piezoelectric composition according to this embodiment, the density of the piezoelectric composition can be made 4.60 g / cm 3 or more, and characteristics at a practical level can be obtained as a piezoelectric device.

[0036] Also, in this embodiment, by setting the range of j, which is the content of Mn, within the above range, the firing temperature when forming the piezoelectric composition can be lowered, and the sinterability is improved. Further, by setting the range of k, which is the content of Ag, within the above range, the sinterability of the piezoelectric composition is further improved, and the density and piezoelectric constant d 33 can be increased.

[0037] Note that Mn may enter the A site and / or B site of the perovskite structure, or may be contained within grains or grain boundaries.

[0038] The composition of the piezoelectric composition according to this embodiment can be measured using a fluorescent X-ray device, an ICP emission spectroscopic analyzer, etc. Also, the crystal structure can be measured using an X-ray diffractometer.

[0039] Next, the manufacturing method of the piezoelectric composition according to this embodiment will be described. When manufacturing a piezoelectric composition, first, raw material powders are weighed and prepared so that the values ​​of a to k in the above composition formula A satisfy the above conditions. Reagent powders such as Na2CO3, K2CO3, BaCO3, Li2CO3, Bi2O3, Nb2O5, Sb2O5, Ta2O5, ZrO2, TiO2, MnO2, and Ag2O can be used as raw materials. Note that these raw materials are merely examples, and powders of other compounds may also be used as raw materials in this embodiment.

[0040] Next, the weighed raw material powders are wet-mixed in alcohol using a ball mill or the like. The mixed powder is then dried and pre-fired at a predetermined temperature (e.g., preferably 800°C to 950°C, more preferably 850°C to 950°C). The resulting pre-fired body is pulverized in alcohol using a ball mill. The pulverized powder is then dried, and an aqueous binder is added. The powder is placed in a mold of a predetermined shape and press-molded under a predetermined pressure (e.g., 200 MPa). The molded sample is then heat-treated at a predetermined temperature (e.g., 500°C) to decompose the binder, and then fired at a predetermined temperature (e.g., preferably 1000°C to 1100°C, more preferably 1050°C to 1100°C). In this manner, the piezoelectric composition according to this embodiment can be produced. The piezoelectric composition according to this embodiment can be fired at a lower temperature than conventional firing temperatures (approximately 1200°C to 1300°C).

[0041] Next, a piezoelectric device according to this embodiment will be described. The piezoelectric device according to this embodiment includes the above-mentioned piezoelectric composition and an electrode for applying a voltage to the piezoelectric composition. In this case, the piezoelectric composition and a plurality of electrodes may be alternately stacked. In other words, a configuration (stack structure) in which layers of the piezoelectric composition and electrode layers are alternately stacked may be used. In addition, the piezoelectric composition according to this embodiment can be applied to various piezoelectric devices. Furthermore, the multilayer actuator according to this embodiment includes the above-mentioned piezoelectric composition and an electrode for applying a voltage to the piezoelectric composition, and has a configuration in which the piezoelectric composition and a plurality of electrodes are alternately stacked. In this embodiment, a multilayer actuator may be formed by further stacking a plurality of multilayer actuators.

[0042] The multilayer actuator according to this embodiment can be manufactured by alternately stacking the above-described piezoelectric composition and a plurality of electrodes, but can also be manufactured as follows.

[0043] First, raw material powders are weighed and prepared so that the values ​​of a to j in the above composition formula A satisfy the above conditions. Reagent powders such as Na2CO3, K2CO3, BaCO3, Li2CO3, Bi2O3, Nb2O5, Sb2O5, Ta2O5, ZrO2, TiO2, and MnO2 can be used as raw materials. Note that these raw materials are merely examples, and powders of other compounds may also be used as raw materials in this embodiment.

[0044] Next, a laminate is produced in which the raw material powder and the internal electrodes containing silver are alternately stacked. The production procedure can be performed, for example, as follows.

[0045] First, the weighed raw material powders are wet-mixed in alcohol using a ball mill or the like. The mixed powder is then dried and pre-fired at a predetermined temperature (e.g., 800°C to 950°C, preferably 850°C to 950°C). The resulting pre-fired body is pulverized in alcohol using a ball mill. The pulverized powder is then dried and mixed with a binder and a solvent to prepare a slurry. The prepared slurry is then applied to a PET film using a doctor blade and dried to form a piezoelectric film. Next, a silver-containing internal electrode (e.g., a silver-palladium alloy paste containing 70% Ag and 30% Pd) is applied to the piezoelectric film, and the applied internal electrode is cut out to a predetermined size. In this way, the formation of the piezoelectric film and the formation of the internal electrode are repeated to stack them, and then hot-pressed. The binder component is then volatilized at 500°C to form a laminate.

[0046] Next, the laminate is fired at a predetermined temperature (for example, preferably 1000°C to 1100°C, more preferably 1050°C to 1100°C). At this time, silver is diffused from the internal electrodes. The firing temperature and time are adjusted appropriately to diffuse silver from the internal electrodes so that the fired body of the raw material powder contains kmol% of silver element per 1 mol of the main component. Thereafter, silver paste is applied to a pair of opposing side surfaces of the fired body and fired to form external electrodes. A laminated actuator can be manufactured by polarization in a predetermined electric field (for example, 2 kV / mm). [Example]

[0047] <Preparation of each sample> Samples according to Examples 1 to 26 and Comparative Examples 1 to 21 were prepared using the following method. First, in the following composition formula A, each raw material powder was weighed out so that the values ​​of a to i were the values ​​(molar ratios) shown in Tables 1 and 2. Furthermore, Mn raw material powder and Ag raw material powder were weighed out so that 1 mol of the composition represented by the following composition formula A contained jmol% of manganese and kmol% of silver (values ​​shown in Tables 1 and 2). The raw materials used were reagent powders of Na2CO3, K2CO3, BaCO3, Li2CO3, Bi2O3, Nb2O5, Sb2O5, Ta2O5, ZrO2, TiO2, MnO2, and Ag2O.

[0048] Composition formula A: {(Na a K b ) 1-c-d Ba c (Bi 0.5 Li 0.5 ) d} e (Nb 1-f-g Sb f Ta g ) 1-h-i Zr h Ti i O3

[0049] Next, the weighed raw material powders were wet-mixed in alcohol using a ball mill. The mixed powder was then dried, pre-fired at 900°C, and further pulverized in alcohol using a ball mill. The pulverized powder was dried, and then an aqueous binder was added. It was then press-molded into a 12 mm diameter disk at a pressure of 200 MPa. After molding, the disk-shaped sample was heat-treated at 500°C to decompose the binder, and then fired at 1070°C.

[0050] <Measurement of each sample> After firing, the density of each sample was measured using the Archimedes method. The density of each sample is shown in Tables 1 to 3. The density units in Tables 1 to 3 are g / cm. 3 is.

[0051] In addition, gold electrodes were formed on the top and bottom surfaces of each sample using a sputtering device. Then, a voltage of 2 kV / mm was applied to perform polarization treatment, and the samples were then polarized using a d 33 The piezoelectric constant d 33The piezoelectric constant d of each sample was measured. 33 are shown in Tables 1 to 3. 33 The unit is pm / V.

[0052] Furthermore, for the samples of Examples 2 to 4 and Comparative Example 1 listed in Table 1, the capacitance was measured with an LCR meter in the temperature range of -50°C to 145°C, and the relative dielectric constant of each sample was calculated. The temperature characteristics of the relative dielectric constant of each sample are shown in Figure 1. In Figure 1, the horizontal axis represents temperature [°C], and the vertical axis represents the relative dielectric constant.

[0053] [Table 1]

[0054] [Table 2]

[0055] [Table 3]

[0056] <Consideration> [density and piezoelectric constant d 33 ] In each sample shown in Table 1, the values ​​of a to j are fixed and the value of k is changed. In other words, the amount of Ag (k value) is changed. In Table 1, the density is 4.60 g / cm 3 and above and d 33 The samples with a value of more than 400 pm / V are examples, and the other samples are comparative examples.

[0057] As shown in Table 1, in Examples 1 to 4 (k = 0.3 to 3.4), the density was 4.60 g / cm 3 This is the above, and d 33 The values ​​were also greater than 400 pm / V, which was a good result.

[0058] In Comparative Example 1, the density was 4.60 g / cm 3 is less than d 33The value was also 400 pm / V or less. This is thought to be because Ag was not included.

[0059] In Comparative Example 2, d 33 was greater than 400 pm / V, but the density was 4.60 g / cm 3 The reason for the low density is thought to be that the amount of Ag was too high.

[0060] In each sample shown in Table 2, the Ta content (g value) was fixed at g = 0.05, the Zr content (h value) was fixed at h = 0.06, the Ti content (i value) was fixed at i = 0.02, the Mn content (j value) was fixed at j = 2, and the Ag content (k value) was fixed at k = 2.5 (corresponding to Example 3), and the values ​​of a to f were changed. 3 and above and d 33 The samples with a value of more than 400 pm / V are examples, and the other samples are comparative examples.

[0061] The amount of Na (a value) was changed in the range of 0.3 to 0.7 in Comparative Examples 3 and 4 and Examples 5 and 6. From these results, it was found that the range of 0.4 to 0.6 was a good range for the amount of Na (a value).

[0062] The amount of K (b value) was changed in the range of 0.3 to 0.7 in Comparative Examples 5 and 6 and Examples 7 and 8. From these results, it was found that the amount of K (b value) was good in the range of 0.4 to 0.6.

[0063] The Ba amount (c value) was changed in the range of 0.03 to 0.09 in Comparative Examples 7 and 8 and Examples 9 and 10. From these results, it was found that the Ba amount (c value) was preferably in the range of 0.04 to 0.08.

[0064] Comparative Examples 9 and 10 and Examples 11 and 12 are Bi 0.5 Li 0.5 The amount (d value) was changed in the range of 0 to 0.05. From these results, Bi 0.5 Li 0.5 The amount (d value) was in the range of 0.01 to 0.04.

[0065] The amount of A sites (e value) was changed in the range of 0.9 to 1.1 in Comparative Examples 11 and 12 and Examples 13 and 14. From these results, it was found that the range of the amount of A sites (e value) was favorable in the range of 0.95 to 1.05.

[0066] The Sb amount (f value) was changed in the range of 0.01 to 0.04 in Comparative Example 13 and Examples 15 to 17. Considering these results and Example 7, the Sb amount (g value) was found to be in the range of 0 to 0.03.

[0067] For each sample shown in Table 3, the Na content (a value) was set to a = 0.5, the K content (b value) to b = 0.5, the Ba content (c value) to c = 0.06, and the Bi 0.5 Li 0.5 The amount of Sb (d value) was fixed at d = 0.02, the amount of A site (e value) was fixed at e = 1, the amount of Sb (f value) was fixed at f = 0, and the amount of Ag (k value) was fixed at k = 2.5 (corresponding to Example 3), and the values ​​of g to j were changed. 3 and above and d 33 The samples with a value of more than 400 pm / V are examples, and the other samples are comparative examples.

[0068] The amount of Ta (g value) was changed in the range of 0.02 to 0.08 in Comparative Examples 14 and 15 and Examples 18 and 19. From these results, it was found that the range of 0.04 to 0.06 was a good range for the amount of Ta (g value).

[0069] The Zr amount (h value) was changed within a range of 0.03 to 0.09 in Comparative Examples 16 and 17 and Examples 20 and 21. From these results, it was found that the Zr amount (h value) was preferably within a range of 0.04 to 0.08.

[0070] The Ti amount (i value) was changed within a range of 0 to 0.05 in Comparative Examples 18 and 19 and Examples 22 and 23. From these results, it was found that the Ti amount (i value) was preferably within a range of 0.01 to 0.04.

[0071] In Comparative Examples 20 and 21 and Examples 24 to 26, the Mn amount (j value) was changed within the range of 0.5 to 5. From these results, it was found that the Mn amount (j value) in the range of 1 to 4 was a good range.

[0072] [Temperature characteristics of dielectric constant] As shown in Figure 1, the behavior of the relative dielectric constant with respect to temperature changed depending on the Ag content (k value). In particular, there was a temperature at which the relative dielectric constant reached its maximum in Examples 2 and 3 and Comparative Example 1. This temperature was the phase transition temperature T R-T The phase transition temperature T of each sample obtained from Figure 1 corresponds to R-T was 19°C in Comparative Example 1, 41°C in Example 2, and 51°C in Example 3. That is, when the Ag amount (k value) is in the above range, the phase transition temperature T R-T This result indicates that the phase transition temperature T R-T This shows that it is possible to design

[0073] Furthermore, the difference between the maximum and minimum values ​​of the relative dielectric constant in the range of actual use temperatures (20 to 90°C) was 460 for Comparative Example 1, 100 for Example 2, 20 for Example 3, and 240 for Example 4. That is, the samples of Examples 2 to 4 showed less change in properties at actual use temperatures and were more stable than Comparative Example 1. This result indicates that by setting the Ag amount (k value) within the above range, the temperature dependency of the relative dielectric constant can be reduced and properties can be stabilized. This allows for greater design freedom and improved quality when applied to various products.

[0074] <Fabrication of stacked actuators> The stacked actuator was fabricated using the following method. First, each raw material powder was weighed out so that the values ​​of a to i (molar ratio) in the above composition formula A satisfied those of Example 3 in Table 1, and the Mn content j per 1 mol of the main component represented by composition formula A was j = 2 mol%. The raw materials used were reagent powders of Na2CO3, K2CO3, BaCO3, Li2CO3, Bi2O3, Nb2O5, Sb2O5, Ta2O5, ZrO2, TiO2, and MnO2. No Ag was added to the raw material powders.

[0075] Next, the weighed raw material powders were wet-mixed in alcohol using a ball mill or the like. The mixed powder was then dried, pre-fired at 900°C, and further pulverized in alcohol using a ball mill. The pulverized powder was dried and then mixed with a binder and solvent to produce a slurry. The produced slurry was then applied to a PET film using a doctor blade and dried to form a piezoelectric film. A silver-palladium alloy paste (Ag70%Pd30% alloy) for the internal electrodes was then applied to the piezoelectric film. The applied internal electrodes were cut to the specified dimensions. The piezoelectric film and internal electrode formation were then repeated to stack these, and a laminate was formed by hot pressing.

[0076] Next, the binder components were volatilized at 500°C. The product was then fired in a firing furnace at 1120°C. Silver paste was then applied to one pair of opposing sides of the fired body and baked to form external electrodes, followed by polarization at 2 kV / mm. The fabricated stacked actuator had 20 active layers, each 100 μm thick, an inactive layer 100 μm thick, and dimensions (length x width x thickness) of 5 mm x 5 mm x 2.2 mm.

[0077] The piezoelectric composition contained in the fabricated multilayer actuator, i.e., the sintered body of the raw material powder, was subjected to structural observation and composition analysis using SEM-EDX. Before the analysis, the cross section was mirror-polished and thermally etched at 1000°C.

[0078] In the SEM image, no particles (coarse particles) more than 10 times the average particle size were observed, and it was confirmed that there was little segregation on the order of μm. Furthermore, EDX analysis confirmed that Ag was uniformly dispersed in the sintered body regardless of the distance from the internal electrode. The concentration of Ag was 1.0 mol% per 1 mol of the main component represented by composition formula A.

[0079] In addition, the density and d 33 The density was measured to be 4.64 g / cm 3 , d 33The value was 494 pm / V. This is thought to be because the a to j values ​​and the k value (Ag amount) contained in the piezoelectric composition were each within a suitable range.

[0080] The present invention has been described above in accordance with the above-mentioned embodiment, but the present invention is not limited to the configuration of the above-mentioned embodiment, and naturally includes various modifications, alterations, and combinations that a person skilled in the art can make within the scope of the invention as defined in the claims of this application.

Claims

1. A piezoelectric composition comprising a composition represented by the following composition formula A as a main component, and containing j mol % of manganese element and kmol % of silver element per 1 mol of the main component. Composition A: {(Na ａ K ｂ ) １－ｃ－ｄ Ba ｃ (Bi) ０．５ Li ０．５ ) ｄ } ｅ (Nb) １－ｆ－ｇ Sb ｆ Ta ｇ ) １－ｈ－ｉ Zr ｈ Ti ｉ O ３ Here, 0.3<a<0.7, 0.3<b<0.7, 0.03<c<0.09, 0<d<0.05, 0.9<e<1.1, 0≦f<0.04, 0.02<g<0.08, 0.03<h<0.09, 0<i<0.05, 0.5<j<5, 0<k<5.

2. 2. The piezoelectric composition according to claim 1, wherein, in composition formula A, 0.4≦a≦0.6, 0.4≦b≦0.6, 0.04≦c≦0.08, 0.01≦d≦0.04, 0.95≦e≦1.05, 0≦f≦0.03, 0.04≦g≦0.06, 0.04≦h≦0.08, 0.01≦i≦0.04, 1≦j≦4, and 0<k<4.

3. The piezoelectric constant d of the piezoelectric composition ３３ The piezoelectric composition according to claim 1 or 2, wherein the value of the σ is greater than 400 pm / V.

4. The density of the piezoelectric composition is 4.60 g / cm ３ The piezoelectric composition according to claim 1 or 2, wherein

5. The piezoelectric composition according to claim 1 or 2, and an electrode for applying a voltage to the piezoelectric composition. Piezoelectric devices.

6. The piezoelectric composition and a plurality of the electrodes are alternately laminated. The piezoelectric device according to claim 5 .

7. The piezoelectric composition according to claim 1 or 2, an electrode for applying a voltage to the piezoelectric composition, The piezoelectric composition and a plurality of the electrodes are alternately laminated. Stacked actuator.

8. preparing a raw material powder having a composition represented by the following composition formula A as a main component, the raw material powder having a molar composition ratio of j mol % manganese and kmol % silver per 1 mol of the main component; pre-firing the raw material powder at 800°C to 950°C; A step of crushing the pre-calcined body obtained by the pre-calcination; pressing the pulverized powder into a compact; and firing the compact at 1000 ° C to 1100 ° C. A method for producing a piezoelectric composition. Composition A: {(Na ａ K ｂ ) １－ｃ－ｄ Ba ｃ (Bi) ０．５ Li ０．５ ) ｄ } ｅ (Nb) １－ｆ－ｇ Sb ｆ Ta ｇ ) １－ｈ－ｉ Zr ｈ Ti ｉ O ３ Here, 0.3<a<0.7, 0.3<b<0.7, 0.03<c<0.09, 0<d<0.05, 0.9<e<1.1, 0≦f<0.04, 0.02<g<0.08, 0.03<h<0.09, 0<i<0.05, 0.5<j<5, 0<k<5.

9. preparing a raw material powder containing a composition represented by the following composition formula A as a main component, with a molar composition ratio of j mol % of manganese per 1 mol of the main component; a step of alternately stacking the raw material powder and internal electrodes containing silver to produce a laminate; and firing the laminate at 1000°C to 1100°C. In the step of firing the laminate, silver is diffused from the internal electrodes so that the fired body of the raw material powder contains kmol% of silver element per 1 mol of the main component. Method for manufacturing stacked actuators. Composition A: {(Na ａ K ｂ ) １－ｃ－ｄ Ba ｃ (Bi) ０．５ Li ０．５ ) ｄ } ｅ (Nb) １－ｆ－ｇ Sb ｆ Ta ｇ ) １－ｈ－ｉ Zr ｈ Ti ｉ O ３ Here, 0.3<a<0.7, 0.3<b<0.7, 0.03<c<0.09, 0<d<0.05, 0.9<e<1.1, 0≦f<0.04, 0.02<g<0.08, 0.03<h<0.09, 0<i<0.05, 0.5<j<5, 0<k<5.

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