阅读说明：本技术 压电组合物及压电元件 (Piezoelectric composition and piezoelectric element ) 是由 广瀬正和 广瀬维子 加藤浩辉 于 2018-03-20 设计创作，主要内容包括：本发明提供一种能够兼顾机械强度和机电耦合系数k<Sub>31</Sub>的压电组合物、具备该压电组合物的压电元件。所述压电组合物其特征在于,含有具有以通式ABO<Sub>3</Sub>表示的钙钛矿结构的复合氧化物和锰,ABO<Sub>3</Sub>中的A位点元素为钾或为钾及钠,B位点元素为铌,压电组合物中,锰的浓度分布具有不均,该不均以CV值计为35％以上440％以下。(The present invention, which provides one kind, can take into account mechanical strength and electromechanical coupling factor k 31 Piezoelectric composition, have the piezoelectric element of the Piezoelectric composition.The Piezoelectric composition is it is characterized in that, containing having with general formula ABO 3 The composite oxides and manganese of the perovskite structure of expression, ABO 3 In the site A element is potassium or is potassium and sodium, the site B element is niobium, and in Piezoelectric composition, the concentration distribution of manganese has unevenness, which is calculated as 35% or more 440% or less with CV value.)

1. a kind of Piezoelectric composition, which is characterized in that

The Piezoelectric composition contains: having with general formula ABO₃The composite oxides and manganese of the perovskite structure of expression,

The ABO₃In the site A element is potassium or is potassium and sodium, the site B element is niobium,

In the Piezoelectric composition, the concentration distribution of the manganese has a unevenness, the unevenness with CV value be calculated as 35% or more 440% with Under.

2. Piezoelectric composition according to claim 1, which is characterized in that

The ABO₃With composition formula (K_xNa_y)NbO₃It indicates, the x and the y in composition formula meet 0.500≤x≤1.005, y ≤ 0.500, the relationship of 0.980≤x+y≤1.005.

3. Piezoelectric composition according to claim 1 or 2, which is characterized in that

Relative to 1 mole of the composite oxides, the manganese is with MnO₂Conversion contains z moles of %,

The z meets the relationship of 0.50≤z≤2.50.

4. Piezoelectric composition described in any one of claim 1 to 3, which is characterized in that

The Piezoelectric composition contains copper,

Relative to 1 mole of the composite oxides, the copper contains n moles of % with CuO conversion,

The n meets the relationship of 0.20≤n≤0.80.

5. a kind of piezoelectric element, wherein

Contain Piezoelectric composition according to any one of claims 1 to 4.

Technical field

The present invention relates to a kind of Piezoelectric composition and with the piezoelectric element of the Piezoelectric composition.

Background technique

Spontaneous polarization caused by offset of the Piezoelectric composition based on the charge in crystallization has by being answered from outside Power and surface generate charge effect (piezoelectric effect) and by from it is external apply electric field and generate effect (the inverse piezoelectricity of deformation Effect).

The piezoelectric element of this Piezoelectric composition that mechanical displacement can be mutually converted with dielectric displacement is applied various It is widely used in field.For example, the actuator as the piezoelectric element using inverse piezoelectric effect is proportional to voltage is applied, Small displacement, and fast response time are accurately obtained, therefore, the driving for optical system components is used, the head of HDD drives Used with the head driving of, ink-jet printer, fuel injection valve driving with etc..

In addition, also serving as the sensor for being used to read small power or deflection using piezoelectric effect.In addition, piezoelectricity combines Object has excellent responsiveness, therefore, can also be by Piezoelectric composition itself or and Piezoelectric composition by applying AC field Elastomer in engagement relationship excites and causes to resonate, and also serves as piezoelectric transformer, ultrasonic motor etc..

In general, Piezoelectric composition is made of polycrystal, by implementing at polarization to the ferroelectric composition after firing It manages and obtains.In ferroelectric composition after firing, the direction of the spontaneous polarization respectively crystallized be it is random, as ferroelectric combine Object is whole, and the offset of charge will not occur, piezoelectric effect and inverse piezoelectric effect will not be presented.Therefore, it carries out by after to firing Ferroelectric composition apply the DC electric field of coercive electric field or more, make the direction of spontaneous polarization and certain orientation be consistent is claimed For the operation of polarization process.Ferroelectric composition after polarization process can show the property as Piezoelectric composition.

As Piezoelectric composition, most use is by lead zirconates (PbZrO₃) and lead titanates (PbTiO₃) constitute lead class piezoelectricity Composition.But lead class Piezoelectric composition contains the low-melting lead oxide (PbO) of the degree of 60~70 weight %, is being burnt into When, lead oxide is readily volatilized.Therefore, from the viewpoint of carrying capacity of environment, the unleaded of Piezoelectric composition becomes extremely important Project.

On the other hand, recently as the Piezoelectric composition of unleaded environment-friendly type, the compound of niobic acid alkali metal class is carried out Research.For example, disclosing a kind of Piezoelectric composition in patent document 1, the compound with niobic acid alkali metal class is as master Phase also has the first oxide phase containing Si and the second oxide phase containing second family element and tetrels.

Summary of the invention

Problems to be solved by the invention

In order to realize high performance, the miniaturization of the equipment for carrying the piezoelectric element with Piezoelectric composition, need tieing up In the state of holding the performance of piezoelectric element, the size of piezoelectric element is reduced.In this case, the size of Piezoelectric composition is needed Become smaller, but when the size of Piezoelectric composition becomes smaller, the mechanical strength of Piezoelectric composition can reduce.When mechanical strength reduces, It is possible to generate substandard products when processing Piezoelectric composition.Therefore, scheduled piezoelectric property is required to Piezoelectric composition and had Good mechanical strength.

But although the compound of niobic acid alkali metal class disclosed in patent document 1 carries out electromechanical coupling factor Evaluation, but any evaluation is not carried out for mechanical strength.The compound of niobic acid alkali metal class in firing, wave by alkali metal element Hair, so that the inside of the Piezoelectric composition after firing is easy to produce gap, defect etc..Therefore, the Piezoelectric composition after firing Whether there is scheduled mechanical strength to be very important.

The present invention is researched and developed in view of this actual state, its purpose is to provide one kind can take into account mechanical strength and Electromechanical coupling factor k₃₁Piezoelectric composition, have the piezoelectric element of the Piezoelectric composition.

A technical solution to solve project

In order to achieve the above objectives, Piezoelectric composition of the invention is following Piezoelectric composition.

[1] a kind of Piezoelectric composition, which is characterized in that

The Piezoelectric composition contains: having with general formula ABO₃The composite oxides and manganese of the perovskite structure of expression,

ABO₃In the site A element is potassium or is potassium and sodium, the site B element is niobium,

In Piezoelectric composition, the concentration distribution of manganese has unevenness, which is calculated as 35% or more 440% or less with CV value.

[2] Piezoelectric composition according to [1], which is characterized in that ABO₃With composition formula (K_xNa_y)NbO₃It indicates, composition X and y in formula meet the relationship of 0.500≤x≤1.005, y≤0.500,0.980≤x+y≤1.005.

[3] Piezoelectric composition according to [1] or [2], which is characterized in that relative to 1 mole of composite oxides, manganese with MnO₂Conversion contains z moles of %,

The relationship of z satisfaction 0.50≤z≤2.50.

[4] Piezoelectric composition according to any one of [1]~[3], which is characterized in that Piezoelectric composition contains copper,

Relative to 1 mole of composite oxides, copper contains n moles of % with CuO conversion,

The relationship of n satisfaction 0.20≤n≤0.80.

[5] a kind of piezoelectric element contains Piezoelectric composition described in any one of [1]~[4].

The effect of invention

Piezoelectric composition through the invention has above-mentioned feature, and can provide can take into account mechanical strength and electromechanical coupling Close coefficient k₃₁Piezoelectric composition, have the piezoelectric element of the Piezoelectric composition.

Detailed description of the invention

Fig. 1 is the schematical perspective view of an example of the piezoelectric element of present embodiment.

Fig. 2 is the schematical cross-sectional view of other examples of the piezoelectric element of present embodiment.

Specific embodiment

Hereinafter, being based on specific embodiment, the present invention is explained in detail according to sequence below.

1. piezoelectric element

1.1 Piezoelectric composition

2. the manufacturing method of piezoelectric element

3. the effect of present embodiment

4. variation

(1. piezoelectric element)

Firstly, being illustrated to the piezoelectric element for the Piezoelectric composition for applying present embodiment.As piezoelectric element, only If can be just not particularly limited using the element of the Piezoelectric composition of present embodiment.In present embodiment, such as example Piezoelectric transformer, thin film sensor, piezoelectric ultrasonic motor etc..

Piezoelectric element 5 shown in FIG. 1 has the piezoelectric portion 1 of plate and is formed in two interareas as piezoelectric portion 1 A pair of of opposite face 1a, 1b a pair of electrodes 2,3.Piezoelectric portion 1 is made of the Piezoelectric composition of present embodiment, piezoelectricity combination The details of object are described in detail below.In addition, the conductive material contained in electrode 2,3 is not particularly limited, can according to desired characteristic, Purposes etc. is arbitrarily set.In present embodiment, example gold (Au), silver (Ag) and palladium (Pd) etc..

In Fig. 1, piezoelectric portion 1 has rectangular shape, but the shape of piezoelectric portion 1 is not particularly limited, being capable of basis Desired characteristic, purposes etc. are arbitrarily set.In addition, the size of piezoelectric portion 1 is it is not also specifically limited, can be according to desired Characteristic, purposes etc. are arbitrarily set.

Piezoelectric portion 1 is along scheduled direction polarization.For example, in piezoelectric element 5 shown in FIG. 1, along the thickness of piezoelectric portion 1 Spend direction, the i.e. opposite direction polarization of electrode 2,3.Such as through the external power supply (not shown) such as not shown electric wire and electrode 2, 3 electrical connections, apply scheduled voltage via 2,3 pairs of piezoelectric portions 1 of electrode.Upon application of a voltage, in piezoelectric portion 1, pass through Inverse piezoelectric effect, electric potential shifting change mechanical displacement into, and piezoelectric portion 1 can laterally carry out oscillation crosswise.

(1.2 Piezoelectric composition)

The Piezoelectric composition of present embodiment, which contains, to be had with general formula ABO₃The composite oxides of the perovskite structure of expression As principal component.In present embodiment, principal component be relative to Piezoelectric composition 100mol%, occupy 90mol% or more at Point.

In perovskite structure, the biggish element of ionic radius, such as alkali metal element, alkali earth metal in occupying ABO₃The site A tendency, the lesser element of ionic radius, such as transition metal element in occupying ABO₃B site incline To.Moreover, the BO being made of the site B element and oxygen₆Oxygen octahedra, which is constituted, shares the three-dimensional network on mutual vertex, by this The gap of network fills the site A element, to form perovskite structure.

In present embodiment, general formula ABO₃It can be with composition formula (K_xNa_y)NbO₃It indicates.That is, the site A element be potassium (K) and Sodium (Na), the site B element are niobium (Nb).

In above-mentioned composition formula, " x " indicates the ratio of the atomicity of K in the site A.On the other hand, " y " is indicated in the site A The ratio of the atomicity of Na.Therefore, in above-mentioned composition formula, " x+y " indicates the total atom number of the site A element relative to the site B Ratio, the so-called A/B ratio of the total atom number of element.That is, total atom number of the sum of the atomicity of the atomicity and Na of K relative to Nb Ratio.In present embodiment, " x+y " preferably satisfies the relationship of 0.980≤x+y≤1.005.In addition, " x+y " is more preferably 0.991 or more, further preferably 0.993 or more.On the other hand, " x+y " is more preferably 0.999 hereinafter, further preferably 0.997 or less.

In present embodiment, by the way that the higher machine of Piezoelectric composition can be taken into account in range that A/B ratio is set as to above-mentioned Tool intensity and good electromechanical coupling factor k₃₁。

In present embodiment, " x " preferably satisfies the relationship of 0.500≤x≤1.005.In addition, " x " be preferably 0.800 with On, more preferably 0.980 or more.On the other hand, " x " is preferably 1.000 hereinafter, more preferably 0.995 or less.

In addition, in present embodiment, " y's " ranges preferably from 0.500 hereinafter, more preferably 0.190 hereinafter, further excellent It is selected as 0.100 or less.From the viewpoint of the mechanical strength of Piezoelectric composition, " y " is particularly preferably 0.000.In addition, " y " is When 0.000, the site A element is only K.

In addition, the Piezoelectric composition of present embodiment contains manganese (Mn).In present embodiment, in Piezoelectric composition, Mn It is preferably in the intercrystalline crystal boundary for constituting composite oxides.It is present in crystal boundary by Mn, intercrystalline binding force becomes strong, energy Enough improve the mechanical strength of Piezoelectric composition.It is present in specific crystal boundary with Mn, and only improves specific intercrystalline binding force It compares, such effect is got over the quantity for the crystal grain for being scattered in crystal boundary by Mn and improving binding force with high concentration presence It is mostly and more big.

In order to increase the quantity for the crystal grain for improving binding force, preferably Mn is not solid-solution in composition composite oxides as much as possible Crystal grain, and Mn equably and with high concentration be present in the intercrystalline formed crystal boundary.Particularly preferred Mn be present in 3 with On intercrystalline formed triple point.Be be formed in due to Mn can have in triple point amount ratio it is two adjacent intercrystalline The amount that Mn can have in crystal boundary is more, and 3 or more crystal grain can be effectively combined via triple point.

Therefore, in present embodiment, using the existence of Mn as described above as the Mn concentration in Piezoelectric composition Unevenness is evaluated.The unevenness can be expressed as CV value, and in present embodiment, CV value is 35% or more 440% or less.In addition, CV value is preferably 170% or more, and more preferably 250% or more.On the other hand, CV value is preferably 360% or less.

By can be improved the mechanical strength of Piezoelectric composition in range that CV value is set as to above-mentioned.In addition, in CV value mistake In the case where big, the ingredient for being helpless to piezoelectric property is largely present in Piezoelectric composition, therefore, deteriorates in piezoelectric property Tendency.

As the method for calculating CV value, as long as the method that can measure the Mn concentration distribution in Piezoelectric composition, does not just have There is special limitation.In present embodiment, CV value can pass through EPMA (electron probe microanalyzer (Electron Probe Micro Analyzer)) analysis, it is following to calculate.Firstly, for the section for having cut off sintered Piezoelectric composition, use EPMA device carries out surface analysis to specific region, obtains the letter of the amount (concentration) of the Mn in the measuring point in the region Breath.

According to the information of obtained Mn concentration, calculate the Mn concentration in each measuring point in the region standard deviation and The average value Av of Mn concentration, and CV value is calculated according to following formulas.

CV value (%)=100 × (σ/Av)

In present embodiment, as the multiplying power for carrying out surface analysis, preferably 200 times~5000 times of the visual field is preferably measured It is more than 3, such visual field visual field.

As long as in addition, Mn is present in crystal boundary, existing forms are not particularly limited, but preferably as the segregation phase containing Mn In the presence of.It is segregated in phase, the oxide that Mn can also be used as Mn exists, and can also be used as and exists with the compound of other elements.

In addition, in present embodiment, in order to CV value is set as to above-mentioned range in, when will be relative to above-mentioned combined oxidation 1 mole of object (100 moles of %) with MnO₂When the content of the Mn of conversion is set as z moles of %, " z " preferably satisfy 0.50≤z≤ 2.50 relationship.In addition, " z " is more preferably 0.80 or more.On the other hand, " z " is more preferably 2.00 or less.

In addition, the method as control CV value, other than the range of the content of Mn, the starting material of the aftermentioned Mn of example Range, mixed method, pulverization conditions, firing condition of the average grain diameter of powder etc..

In addition, the Piezoelectric composition of present embodiment can also contain copper (Cu).When will be relative to above-mentioned combined oxidation When the content of the Cu with CuO conversion of 1 mole of object (100 moles of %) is set as n moles of %, " n " preferably satisfies 0.20≤n≤0.80 Relationship.In addition, " n " is more preferably 0.30 or more.On the other hand, " n " is more preferably 0.75 or less.

As long as Cu contains in above-mentioned range, the existing forms of Cu are not particularly limited.In present embodiment, preferably It is solid-solution in the crystal grain for constituting the crystal grain of composite oxides, but crystal boundary can also be present in together with Mn.It is being present in crystal boundary In the case of, compound can also be formed with other elements.But not preferably as with by above-mentioned (K_xNa_y)NbO₃The crystalline substance of composition Mutually different out-phase exists.

It is present in crystal grain by Cu and/or crystal boundary, intercrystalline binding force becomes strong, piezoelectricity combination can be further increased The mechanical strength of object.

The Piezoelectric composition of present embodiment can also contain other ingredients other than above-mentioned ingredient.For example, can also To contain transition metal element (the 3rd race~the 11st race member in long period type periodic table in addition to above-mentioned Nb, Mn and Cu Element), alkali earth metal, the 13rd race's metal member in the 12nd race's element and long period type periodic table in long period type periodic table It is at least one kind of in element.

Specifically, as the transition metal element in addition to rare earth element, example: chromium (Cr), iron (Fe), cobalt (Co), Nickel (Ni), tungsten (W), molybdenum (Mo) etc..As rare earth element, example: yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) etc..

As alkali earth metal, example magnesium (Mg), strontium (Sr) etc..As the 12nd race's element, example zinc (Zn) etc..As 13rd race's metallic element, example aluminium (Al), gallium (Ga), indium (In) etc..

In addition, preferably having in the Piezoelectric composition of present embodiment with general formula ABO₃The perovskite structure of expression is answered It closes oxide and does not contain lithium (Li) actually.Li is not present particularly preferable as the site the A element in perovskite structure.It is specific and Speech, composition formula (K_xNa_yLi_a)NbO₃In, preferred " x+y+a " relationship for meeting 0.980≤x+y+a≤1.005, and " a " is 0.010 or less.It is that in firing, volatilization acutely, generates the tendency in gap in the Piezoelectric composition after firing due to Li.

In this case, " x+y+a " is more preferably 0.991 or more, further preferably 0.993 or more.On the other hand, " x + y+a " is more preferably 0.999 hereinafter, further preferably 0.997 or less.

It can be according to for example being penetrated by the X that XRD determining obtains with the presence or absence of Li as the site the A element in perovskite structure In ray diffraction diagram case, if detect the peak of the perovskite-type compounds containing Li to be judged.

In addition, the Piezoelectric composition of present embodiment can also be used as impurity containing lead (Pb), but its content is preferably 1 weight Amount % is hereinafter, be more preferably entirely free of Pb.It is due to that can incite somebody to action from the viewpoint of low nuisanceless, the feature of environmental protection and ecology The volatilization of Pb when firing, or carry the Piezoelectric composition containing present embodiment piezoelectric element electronic equipment in the market Release of the Pb into environment is suppressed to minimum limit after circulation is discarded.

It is strong from the performance of piezoelectric property, machinery to constitute the average crystallite particle diameter of the crystal grain of the Piezoelectric composition of present embodiment From the viewpoint of degree, as long as being controlled, in present embodiment, average crystallite particle diameter is preferably such as 0.5 μm~20 μm.

(manufacturing methods of 2. piezoelectric elements)

Then, illustrate an example of the manufacturing method of piezoelectric element below.

Firstly, preparing the starting material of Piezoelectric composition.As the starting material of composite oxides, it is able to use containing K Compound, the compound containing Nb be able to use the compound containing Na as needed.As the compound containing K and contain There are compound of Na, such as example carbonate, bicarbonate compound etc..It is aoxidized as the compound containing Nb, such as example Object etc..

As the starting material of manganese, manganese simple substance can be, be also possible to the compound containing manganese.It is excellent in present embodiment It is selected as the oxide containing manganese.In addition, the average grain diameter of the powder of the starting material of manganese is preferably in the range of 0.1~5 μm.

In addition, preparing the starting material of copper in the case where containing copper in Piezoelectric composition.As the starting material of copper, With manganese likewise it is possible to be copper simple substance, it is also possible to the compound containing copper.In present embodiment, preferably containing the oxygen of copper Compound.

By the starting material of the composite oxides of preparation according to scheduled ratio weighing after, using ball mill etc. carry out 5~ It mixes within 20 hours.As mixed method, wet mixed can be, be also possible to dry type mixing.In the case where wet mixed, Mixed powder is dry.Then, formed body obtained from forming to mixed powder or by mixed powder is in an atmosphere with 750~1050 DEG C, 1 ~20 hours conditions are heat-treated (calcining), obtain the calcined powder of composite oxides.

The composite oxides for constituting obtained calcined powder have with general formula KNbO₃Or (K, Na) NbO₃The perovskite of expression Structure.

, it is preferable to use ball mill etc. carries out the calcined powder of predetermined time in the case where obtained calcined powder cohesion It crushes, comminuted powder is made.It adds and mixes former according to the starting of the weighed manganese of scheduled ratio into calcined powder or comminuted powder The starting material of the starting material and copper of material or manganese, obtains the raw material powder of Piezoelectric composition.In present embodiment, as mixing Method, preferably ball mill, ball mill etc..

The molding method of raw material powder of Piezoelectric composition is not particularly limited, as long as according to desired shape, size etc. It is suitable for selection.In the case where being pressed and molded, added into the raw material powder of Piezoelectric composition scheduled adhesive and Additive as needed is shaped to scheduled shape and obtains formed body.Alternatively, it is also possible to use the original to Piezoelectric composition Pelletizing obtained from scheduled adhesive etc. is granulated is added in feed powder, obtains formed body.Also it can according to need, to The formed body arrived passes through the further progresss pressurized treatments such as CIP.

Unsticking mixture process is implemented to obtained formed body.As unsticking mixture condition, temperature will be kept to be preferably set to 400 DEG C~800 DEG C, temperature hold-time is preferably set to 2 hours~4 hours.

Then, it is burnt into the formed body after unsticking mixture process.As firing condition, temperature will be kept to be preferably set to 950 DEG C ~1060 DEG C, temperature hold-time is preferably set to 2 hours~4 hours, heating and cooling rate be preferably set to 50 DEG C/h~ Atmosphere is preferably set to oxygen-containing atmosphere by 300 DEG C/h of degree.In firing condition, temperature is kept by adjusting, can be controlled The CV value of Mn concentration.

The obtained Piezoelectric composition as sintered body is ground as needed, coating electrode cream carries out burn-back, shape At electrode.The method for forming electrode is not particularly limited, and can also form electrode by being deposited, sputtering etc..

The sintered body for being formed with electrode is processed into scheduled size as needed, applies 2kV/ in the oil of predetermined temperature 5 minutes~1 hour degree of electric field of mm~5kV/mm is polarised.After having carried out polarization process, spontaneous pole is obtained Change and the consistent Piezoelectric composition in scheduled direction.

Piezoelectric composition after polarization process is made to the piezoelectric portion 1 of plate.Then, pass through in the piezoelectric portion 1 Vapor deposition etc. forms electrode 2,3, thus, it is possible to obtain piezoelectric element shown in FIG. 1.

(effects of 3. present embodiments)

In present embodiment, as the composite oxides contained in Piezoelectric composition as principal component, using with calcium titanium The compound of the niobic acid alkali metal class of mine structure, in addition, in Piezoelectric composition contain manganese (Mn), and with the CV value of Mn concentration at It is controlled for the mode in above-mentioned range.The CV value of Mn concentration indicates to mix in Piezoelectric composition in above-mentioned range to deposit There is Mn with part existing for low concentration, i.e., to generate unevenness in the concentration distribution of Mn with part and Mn existing for high concentration.Piezoelectricity In composition, Mn is hardly solid-solution in the crystal grain being made of the compound of niobic acid alkali metal class, is present in high concentration in the crystalline substance The crystal boundary that intergranular is formed.

Exist by Mn with concentration distribution as described above, Mn can be improved intercrystalline combination.As a result, as pressure The mechanical strength of electric composition improves.

Piezoelectric composition after firing is processed in the manufacture of such as piezoelectric element etc. sometimes.If Piezoelectric composition is not With good mechanical strength, then work in-process exist occur because the intensity of Piezoelectric composition it is insufficient caused by fragmentation, cracking etc., And lead to the problem of substandard products etc..When generating this substandard products, yield rate reduces and can not achieve higher productivity.In addition, by In repeating application mechanical displacement and dielectric displacement to Piezoelectric composition, therefore, it is necessary to have the intensity for being able to bear these displacements.This The Piezoelectric composition of embodiment due to good mechanical strength, processability is good, can be improved yield rate and mentions The production efficiency of high pressure electric device.In addition, the Piezoelectric composition of present embodiment has the mechanical position for being able to bear repetition application The sufficient intensity of shifting and dielectric displacement.

In addition, the machine of Piezoelectric composition can be well maintained by range that the CV value of Mn concentration is set as to above-mentioned Tool intensity, and improve electromechanical coupling factor k₃₁.That is, the mechanical strength and piezoelectric property of Piezoelectric composition can be taken into account.In the presence of In the Mn of crystal boundary be the ingredient for being helpless to piezoelectric property, therefore, by range that the CV value of Mn concentration is set as to above-mentioned, thus The content of Mn is reduced, and Mn is made to be present in crystal boundary effectively and with high concentration.

In addition, as the accessory ingredient relative to composite oxides, by containing Cu, Piezoelectric composition can be further increased Mechanical strength.

(4. variation)

In above-mentioned embodiment, the piezoelectric element that piezoelectric portion is single layer is illustrated but it is also possible to be having The piezoelectric element of the structure of piezoelectric portion has been laminated.Alternatively, it is also possible to being the piezoelectric element with these structures being composed.

As the piezoelectric element with the structure that piezoelectric portion has been laminated, such as example piezoelectric element 50 shown in Fig. 2.It should Piezoelectric element 50, which has, hands over the multiple piezoelectric layers 11 and multiple internal electrodes 12 that are made of the Piezoelectric composition of present embodiment For the laminated body 10 being laminated.It is formed at the both ends of the laminated body 10 and in the inside of laminated body 10 is alternately arranged A pair of terminal electrode 21,22 that portion's electrode layer 12 is respectively turned on.

The thickness (layer thickness) of each layer of piezoelectric layer 11 is not particularly limited, can be according to desired characteristic and purposes Deng arbitrarily setting.In general, layer thickness is preferably 1 μm~100 μm of degree.The stacking number of piezoelectric layer 11 does not limit especially It is fixed, it can arbitrarily be set according to desired characteristic and purposes etc..

As the method for manufacturing piezoelectric element 50 shown in Fig. 2, as long as using well known method, for example, being fabricated to It for the green compact chip of laminated body 10 shown in Fig. 2, is fired into after laminated body 10, terminal electrode is printed or is needed on Laminated body 10 is simultaneously burnt into, and is thus manufactured.The usual of cream has been used as the method for manufacture green compact chip, such as example Print process, sheet material method etc..In print process and sheet material method, using by the raw material powder of above-mentioned Piezoelectric composition and by adhesive it is molten Cream made of the mixing of solution carrier obtained in solvent and coating, forms green compact chip.

More than, embodiments of the present invention are illustrated, but the present invention is not defined to above-mentioned embodiment party Formula can be changed in various ways within the scope of the invention.