JP2007165553A - Piezoelectric element and its manufacturing method, piezoelectric actuator, and ink-jet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environment-friendly piezoelectric element with excellent piezoelectric characteristics. <P>SOLUTION: The piezoelectric element 1 includes a substrate 2 and a piezoelectric-body film 6 at least including a piezoelectric body formed above the substrate and composed of (Na, K, Li)NbO<SB>3</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a piezoelectric element, a manufacturing method thereof, a piezoelectric actuator, and an ink jet recording head.

Inkjet printers are known as printers that enable high image quality and high-speed printing. The ink jet printer includes an ink jet recording head having a cavity whose internal volume changes. As a head actuator in such an ink jet recording head, a piezoelectric element using a piezoelectric film typified by Pb (Zr, Ti) O ₃ (PZT) has been conventionally used (for example, Japanese Patent No. 3666177). reference). However, since PZT and the like contain lead (Pb), there is a very environmental problem.
Japanese Patent No. 3666177

  An object of the present invention is to provide a piezoelectric element that is environmentally friendly and has good piezoelectric characteristics, and a method for manufacturing the same. Another object of the present invention is to provide a piezoelectric actuator and an ink jet recording head using the piezoelectric element.

The piezoelectric element according to the present invention is
A substrate,
And a piezoelectric film that is formed above the substrate and includes at least a piezoelectric body made of (Na, K, Li) NbO ₃ (hereinafter also referred to as “NKLN”).

In this piezoelectric element, the piezoelectric film includes at least a piezoelectric body made of NKLN. NKLN is extremely useful because it does not contain lead (Pb), which is an environmental problem. Furthermore, NKLN is lead-free, but has a higher Curie temperature and depolarization temperature than, for example, (Bi, K) TiO _3, and can stably operate the piezoelectric element within a predetermined temperature range. Can do. Furthermore, although NKLN is lead-free, it can increase the piezoelectric constant of the piezoelectric element and increase the amount of displacement of the vibrating portion of the piezoelectric element, for example, compared to (Bi, K) TiO ₃ or the like. Thereby, it is possible to obtain a fine piezoelectric element for an ink jet recording head having a high ink discharge capability even at a low voltage. Therefore, according to the present invention, it is possible to provide a piezoelectric element that is environmentally friendly and has various characteristics.

  In the description according to the present invention, the word “upward” refers to, for example, “another specific thing (hereinafter referred to as“ B ”) formed“ above ”a specific thing (hereinafter referred to as“ A ”)”. Etc. In the description of the present invention, in the case of this example, there are a case where B is directly formed on A and a case where B is formed on A via another. The word “above” is used as included.

In the piezoelectric element according to the present invention,
The piezoelectric body can be represented by the following formula.

_{(1-x) (Na,} K) NbO 3 -xLiNbO 3
(However, 0.05 ≦ x ≦ 0.06)
In the piezoelectric element according to the present invention,
x may be a value at a phase boundary of the crystal structure of the piezoelectric body.

In the piezoelectric element according to the present invention,
The piezoelectric body may include cerium oxide.

In the piezoelectric element according to the present invention,
The amount of cerium oxide added to the piezoelectric body may be 0.2 wt% or more and 1 wt% or less.

In the piezoelectric element according to the present invention,
A first conductive layer formed above the substrate and below the piezoelectric film;
And a second conductive layer formed above the piezoelectric film.

The method for manufacturing a piezoelectric element according to the present invention includes:
Forming a first piezoelectric film including a piezoelectric material represented by the following formula (1) above the substrate;
Laminating a material layer for forming a piezoelectric body represented by the following formula (2) above the first piezoelectric film;
Heat-treating the first piezoelectric film and the material layer to form a second piezoelectric film including at least a piezoelectric material represented by the following formula (3).

(Na, K) NbO ₃ (1)
(1-x) (Na, K) NbO ₃ —xLiNbO ₃ (2)
(However, 0.08 ≦ x ≦ 0.10)
(1-x) (Na, K) NbO ₃ —xLiNbO ₃ Formula (3)
(However, 0.05 ≦ x ≦ 0.06)
In the method for manufacturing a piezoelectric element according to the present invention,
The piezoelectric body represented by the formulas (1) to (3) can contain cerium oxide.

In the method for manufacturing a piezoelectric element according to the present invention according to the present invention,
The addition amount of cerium oxide in the piezoelectric body represented by the formula (1) is 0.2 wt% or more and 1 wt% or less,
The amount of cerium oxide added in the piezoelectric body represented by the formula (2) is 0.2 wt% or more and 1 wt% or less,
The addition amount of cerium oxide in the piezoelectric body represented by the formula (3) can be 0.2 wt% or more and 1 wt% or less.

  A piezoelectric actuator according to the present invention includes the above-described piezoelectric element.

  An ink jet recording head according to the present invention includes the above-described piezoelectric element.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1. 1. First embodiment 1.1. First, the piezoelectric element 1 according to the first embodiment will be described. FIG. 1 is a diagram showing an embodiment in which a piezoelectric element according to the present invention is applied to a piezoelectric element 1 that is a head actuator for an ink jet recording head.

  The piezoelectric element 1 includes a substrate 2, an elastic film 3 formed on the substrate 2, a first conductive layer (hereinafter also referred to as “lower electrode”) 4 formed on the elastic film 3, and a lower electrode 4. A formed piezoelectric film (hereinafter also referred to as “second piezoelectric film”) 6 and a second conductive layer (hereinafter also referred to as “upper electrode”) 7 formed on the second piezoelectric film 6 are included. .

  As the substrate 2, for example, a (110) -oriented single crystal silicon substrate can be used, and is not particularly limited. The elastic film 3 can be applied as the elastic film 55 in the ink jet recording head 50 (see FIG. 4). As the elastic film 3, for example, a film in which silicon oxide and zirconium oxide are laminated in this order can be used, and the elastic film 3 is not particularly limited. Here, the silicon oxide layer can function as an etching stopper, for example, in the step of etching the substrate 2 from the back side in order to form the cavity 521 of the ink jet recording head 50. The film thickness of the elastic film 3 is, for example, 1 μm.

The lower electrode 4 is one electrode for applying a voltage to the second piezoelectric film 6. The lower electrode 4 can be formed in the same planar shape as, for example, the second piezoelectric film 6 and the upper electrode 7. As the lower electrode 4, for example, a film in which a conductive oxide having a perovskite structure (for example, LaNiO ₃ , SrRuO _3, etc.) is stacked on platinum (Pt) can be used, and the lower electrode 4 is not particularly limited. The film thickness of the lower electrode 4 is, for example, 100 nm to 200 nm.

The second piezoelectric film 6 includes at least a piezoelectric body made of (Na, K, Li) NbO ₃ (NKLN). The Curie temperature of the piezoelectric body made of NKLN is 300 ° C. or higher.

  A piezoelectric body made of NKLN can be expressed by the following equation, for example.

(1-x) (Na, K) NbO ₃ —xLiNbO ₃ Formula (i)
(However, 0.05 ≦ x ≦ 0.06)
For example, the piezoelectric body represented by the formula (i) can contain cerium oxide. Examples of cerium oxide include cerium dioxide (CeO ₂ ). In this case, for example, the second piezoelectric film 6 can include at least a piezoelectric body represented by the following formula (ii).

(1-x) (Na, K) NbO ₃ —xLiNbO ₃ —CeO ₂ Formula (ii)
(However, 0.05 ≦ x ≦ 0.06)
The addition amount of cerium oxide in the piezoelectric body represented by the formula (ii) is preferably 0.2% by weight or more and 1% by weight or less, more preferably 0.2% by weight or more and 0.8% by weight. It is as follows. By adding cerium oxide within these ranges, the effect of adding cerium oxide (described later) can be stably expressed.

  In the piezoelectric body made of NKLN represented by formula (i) or formula (ii), when x is 0.05 or more and 0.06 or less, the piezoelectric body has a crystal structure (orthorhombic structure and trigonal structure). ) In the phase boundary (MPB: Morphotropic Phase Boundary). That is, x can be a value at the phase boundary of the crystal structure of the piezoelectric body represented by the formula (i) or the formula (ii).

  The second piezoelectric film 6 can be, for example, a film in which the piezoelectric bodies represented by the formula (i) or the formula (ii) are uniformly distributed. The second piezoelectric film 6 has, for example, a gradient composition structure in which the composition continuously changes in the thickness direction. In the gradient composition structure, at least one of the continuously changing compositions is expressed by the formula The composition of the piezoelectric body represented by (i) or formula (ii) can be used.

  In the piezoelectric body represented by the formulas (i) and (ii), the composition ratio of Na and K is preferably, for example, 0.5: 0.5. Thereby, the piezoelectricity of the piezoelectric body can be improved. In this case, the piezoelectric bodies represented by the formulas (i) and (ii) are represented by the following formulas (i ′) and (ii ′), respectively.

(1-x) (Na _0.5 K _0.5 ) NbO ₃ —xLiNbO ₃ Formula (i ′)
(1-x) (Na _0.5 K _0.5 ) NbO ₃ —xLiNbO ₃ —CeO ₂ Formula (ii ′)
The film thickness of the second piezoelectric film 6 is not particularly limited, but is, for example, 200 nm to 400 nm.

The upper electrode 7 is the other electrode for applying a voltage to the second piezoelectric film 6. As the upper electrode 7, for example, a film in which platinum (Pt) is laminated on a conductive oxide having a perovskite structure (for example, LaNiO ₃ , SrRuO _3, etc.) can be used, and the upper electrode 7 is not particularly limited. It is preferable that the layer configuration of the lower electrode 4 and the layer configuration of the upper electrode 7 are substantially symmetrical with respect to the second piezoelectric film 6. For example, when a film in which a conductive oxide having a perovskite structure is stacked on platinum is used as the lower electrode 4, a film in which platinum is stacked on a conductive oxide having a perovskite structure is used as the upper electrode 7. It is preferable. Thereby, the symmetry of the piezoelectric element 1 can be improved. Further, by adopting such a layer configuration, all layers from the upper part of the lower electrode 4 to the lower part of the upper electrode 7 can have a perovskite structure. The film thickness of the upper electrode 7 is, for example, 100 nm to 200 nm.

  1.2. Next, a method for manufacturing the piezoelectric element 1 according to the present embodiment will be described with reference to FIGS. 2 and 3 are cross-sectional views schematically showing one manufacturing process of the piezoelectric element 1 shown in FIG.

  (A) First, as shown in FIG. 2, the elastic film 3 is formed on the substrate 2. The elastic film 3 can be formed by, for example, a thermal oxidation method, a chemical vapor deposition (CVD) method, a sputtering method, a vapor deposition method, or the like.

  (B) Next, the lower electrode 4 is formed on the elastic film 3. The lower electrode 4 can be formed, for example, by sputtering, spin coating, CVD, laser ablation, or the like.

  (C) Next, as shown in FIG. 2, a first piezoelectric film 5 including a piezoelectric body having an orthorhombic structure represented by the following formula (1) is formed on the lower electrode 4.

(Na, K) NbO ₃ (1)
For example, the piezoelectric body represented by the formula (1) can contain cerium oxide. Examples of cerium oxide include cerium dioxide (CeO ₂ ). In this case, a first piezoelectric film 5 including a piezoelectric body represented by the following formula (a) can be formed on the lower electrode 4.

(Na, K) NbO ₃ —CeO ₂ Formula (a)
The addition amount of cerium oxide in the piezoelectric body represented by the formula (a) is preferably 0.2% by weight or more and 1% by weight or less, more preferably 0.2% by weight or more and 0.8% by weight. It is as follows. By adding cerium oxide within these ranges, the effect of adding cerium oxide (described later) can be stably expressed.

  In the piezoelectric body represented by the formulas (1) and (a), the composition ratio of Na and K is preferably, for example, 0.5: 0.5. Thereby, the piezoelectricity of the second piezoelectric film 6 formed in a later process can be improved. In this case, the piezoelectric bodies represented by the expressions (1) and (a) are represented by the following expressions (1 ′) and (a ′), respectively.

(Na _0.5 K _0.5 ) NbO ₃ Formula (1 ′)
(Na _0.5 K _0.5 ) NbO ₃ —CeO ₂ Formula (a ′)
The method for forming the first piezoelectric film 5 is specifically as follows.

  First, for example, a solution obtained by mixing a plurality of raw material solutions at a desired ratio is applied on the lower electrode 4 using a spin coating method or the like so that the first piezoelectric film 5 has a desired composition ratio (mixed solution). Application process). Concerning the raw material solution, the constituent metal of the piezoelectric material to be the first piezoelectric film 5 (in the case of the piezoelectric body represented by the formula (1), Na, K, Nb, the piezoelectric body represented by the formula (a) Is mixed with an organic metal or inorganic metal containing Na, K, Nb, Ce) so that each metal has a desired molar ratio, and this is mixed with an organic solvent such as alcohol (n-butanol, etc.). It can be prepared by dissolving or dispersing. As the organic metal including the constituent metal of the piezoelectric material, for example, a metal alkoxide, an organic acid salt, or the like can be used. Examples of the organic metal or inorganic metal including the constituent metal of the piezoelectric material include the following.

  Examples of the organic metal containing sodium (Na) include sodium ethoxide. Examples of the organic metal containing potassium (K) include potassium ethoxide. Examples of the organic metal containing niobium (Nb) include niobium ethoxide. Examples of inorganic metals containing cerium (Ce) include cerium (IV) ammonium nitrate. Note that the organic metal or inorganic metal including the constituent metal of the piezoelectric material is not limited to these.

  Various additives such as a stabilizer can be added to the raw material solution as necessary. When hydrolysis and polycondensation are caused in the raw material solution, an acid or a base can be added as a catalyst together with an appropriate amount of water to the raw material solution.

  For example, the rotation speed of the spin is initially set to 500 rpm, and subsequently, the rotation speed can be increased to 2000 rpm so that coating unevenness does not occur.

  Next, heat treatment is performed at a temperature (for example, 150 ° C.) higher by 10 ° C. than the boiling point of the solvent used in the raw material solution using a hot plate or the like in an air atmosphere (dry heat treatment step).

  Next, in order to decompose and remove the organic metal and inorganic metal ligands used in the raw material solution, heat treatment is performed at about 300 ° C. to 400 ° C., for example, in an air atmosphere (degreasing heat treatment step). .

  It should be noted that the above-described series of steps of the mixed solution coating step, the drying heat treatment step, and the degreasing heat treatment step can be repeated as appropriate according to the desired film thickness.

  Next, the first piezoelectric film 5 is obtained by performing a crystallization annealing, that is, a baking step for crystallization. The crystallization annealing can be performed at about 600 ° C. to 750 ° C. in an oxygen atmosphere by, for example, RTA (Rapid Thermal Annealing).

  The first piezoelectric film 5 can also be formed using, for example, an immersion method, a sputtering method, a metal organic chemical vapor deposition (MOCVD) method, or the like.

  (D) Next, as shown in FIG. 3, a material layer 8 for forming a piezoelectric body represented by the following formula (2) is laminated on the first piezoelectric film 5.

(1-x) (Na, K) NbO ₃ —xLiNbO ₃ (2)
(However, 0.08 ≦ x ≦ 0.10)
The piezoelectric body represented by the formula (2) has a trigonal structure when crystallized.

For example, the piezoelectric body represented by the formula (2) can contain cerium oxide. Examples of cerium oxide include cerium dioxide (CeO ₂ ). In this case, a material layer 8 for forming a piezoelectric body represented by the following formula (b) can be laminated on the first piezoelectric film 5.

(1-x) (Na, K) NbO ₃ —xLiNbO ₃ —CeO ₂ Formula (b)
(However, 0.08 ≦ x ≦ 0.10)
The addition amount of cerium oxide in the piezoelectric body represented by the formula (b) is preferably 0.2 wt% or more and 1 wt% or less, more preferably 0.2 wt% or more and 0.8 wt%. It is as follows. By adding cerium oxide within these ranges, the effect of adding cerium oxide (described later) can be stably expressed.

  In the piezoelectric body represented by the formulas (2) and (b), the composition ratio of Na and K is preferably 0.5: 0.5, for example. Thereby, the piezoelectricity of the second piezoelectric film 6 formed in a later process can be improved. In this case, the piezoelectric bodies represented by the expressions (2) and (b) are represented by the following expressions (2 ′) and (b ′), respectively.

(1-x) (Na _0.5 K _0.5 ) NbO ₃ —xLiNbO ₃ Formula (2 ′)
(However, 0.08 ≦ x ≦ 0.10)
(1-x) (Na _0.5 K _0.5 ) NbO ₃ —xLiNbO ₃ —CeO ₂ Formula (b ′)
(However, 0.08 ≦ x ≦ 0.10)
The lamination of the material layer 8 can be performed in the same manner as the mixed solution coating process, the drying heat treatment process, and the degreasing heat treatment process in the above-described formation process of the first piezoelectric film 5. Note that examples of the organic metal containing lithium (Li) include lithium ethoxide. In addition, a series of steps including the mixed solution coating step, the drying heat treatment step, and the degreasing heat treatment step can be repeated as appropriate according to the desired film thickness.

  The material layer 8 can also be laminated using, for example, an immersion method, a sputtering method, a metal organic chemical vapor deposition (MOCVD) method, or the like.

  (E) Next, the first piezoelectric film 5 and the material layer 8 are subjected to a heat treatment (crystallization annealing), that is, a firing step for crystallization. As a result, the substances in the first piezoelectric film 5 and the material layer 8 are interdiffused and, as shown in FIG. 1, at least the piezoelectric body represented by the above formula (i) or formula (ii) is included. Two piezoelectric films 6 are formed.

  The crystallization annealing can be performed at about 600 ° C. to 750 ° C. in an oxygen atmosphere by, for example, RTA (Rapid Thermal Annealing).

  (F) Next, as shown in FIG. 1, the upper electrode 7 is formed on the second piezoelectric film 6. The upper electrode 7 can be formed by, for example, sputtering, spin coating, chemical vapor deposition (CVD), laser ablation, or the like.

  Through the above steps, the piezoelectric element 1 according to this embodiment can be manufactured.

1.3. In the piezoelectric element 1 according to the present embodiment, the second piezoelectric film 6 includes at least a piezoelectric body made of NKLN. NKLN is extremely useful because it does not contain lead (Pb), which is an environmental problem. Furthermore, NKLN is lead-free, but has a higher Curie temperature and depolarization temperature than, for example, (Bi, K) TiO _3, and can stably operate the piezoelectric element 1 within a predetermined temperature range. Furthermore, although NKLN is lead-free, it can increase the piezoelectric constant of the piezoelectric element 1 and increase the amount of displacement of the vibration part of the piezoelectric element 1 compared to, for example, (Bi, K) TiO _3. it can. Thereby, it is possible to obtain a fine piezoelectric element 1 for an ink jet recording head having a high ink discharge capability even at a low voltage. Therefore, according to this embodiment, it is possible to provide the piezoelectric element 1 which is environmentally friendly and has various characteristics.

  In the piezoelectric element 1 according to this embodiment, the second piezoelectric film 6 can have NKLN that is a phase boundary composition of a crystal structure. Since the piezoelectricity of NKLN in the vicinity of the phase boundary composition is good, according to this embodiment, the piezoelectric constant of the piezoelectric element 1 can be further increased.

  In addition, according to the method for manufacturing the piezoelectric element 1 according to this embodiment, the second piezoelectric film 6 including at least NKLN that is a phase boundary composition of a crystal structure can be formed. Usually, it is difficult to directly form NKLN, which is a phase boundary composition of a crystal structure, on the lower electrode 4 in a state of good crystallinity. However, according to the present embodiment, first, the first piezoelectric film 5 and the material layer 8 are formed on the lower electrode 4, and then heat treatment is performed, so that the first piezoelectric film 5 and the material layer 8 are formed. The second piezoelectric film 6 containing at least NKLN that is the phase boundary composition can be reliably formed by the method of interdiffusion of these substances.

  In the piezoelectric element 1 according to this embodiment, the second piezoelectric film 6 can have NKLN containing cerium oxide. Thereby, the sinterability in the crystallization annealing step can be improved, the crystal film can be made dense, and the piezoelectricity of the second piezoelectric film 6 can be improved.

  Further, according to the method for manufacturing the piezoelectric element 1 according to the present embodiment, the first piezoelectric film 5 can function as a buffer layer between the lower electrode 4 and the material layer 8. For example, when the material layer 8 is directly laminated and crystallized on the lower electrode 4, compared with the case where the first piezoelectric film 5 is formed on the lower electrode 4 as in the present embodiment, It is difficult to form a film having good crystallinity. On the other hand, according to the present embodiment, the first piezoelectric film 5 is used as a buffer layer, and the material layer 8 is stacked thereon and crystallized, whereby the material layer 8 can be crystallized well. As a result, the second piezoelectric film 6 having good crystallinity can be formed.

2. Second Embodiment 2.1. Next, an example in which the piezoelectric element according to the present invention is applied to an ink jet recording head as a piezoelectric actuator will be described. FIG. 4 is a side sectional view showing a schematic configuration of the ink jet recording head 50 according to the present embodiment, and FIG. It is shown in.

  As shown in FIGS. 4 and 5, the ink jet recording head 50 includes a head main body 57 and a piezoelectric portion 54 formed on the head main body 57. The piezoelectric unit 54 is configured by sequentially stacking the lower electrode 4, the second piezoelectric film 6, and the upper electrode 7 in the piezoelectric element 1 shown in FIG. 1. 4 and 5, illustration of each layer of the piezoelectric portion 54 is omitted. In the ink jet recording head 50, the piezoelectric portion 54 functions as a piezoelectric actuator.

  The head body 57 includes a nozzle plate 51, an ink chamber substrate 52, and an elastic film 55. The ink chamber substrate 52 and the elastic film 55 are composed of the substrate 2 and the elastic film 3 in the piezoelectric element 1 shown in FIG. These are housed in a casing 56 to constitute an ink jet recording head 50.

  Each piezoelectric portion 54 is electrically connected to a piezoelectric element drive circuit (not shown) and is configured to operate (vibrate, deform) based on a signal from the piezoelectric element drive circuit. That is, each piezoelectric part 54 functions as a vibration source (head actuator). The elastic film 55 vibrates due to the vibration (deflection) of the piezoelectric portion 54 and functions to instantaneously increase the internal pressure of the cavity 521.

  2.2. The ink jet recording head 50 according to the present embodiment includes a fine piezoelectric element 1 that is environmentally friendly and has a high ink discharge capability even at a low voltage. Thereby, it is possible to provide a device (for example, an ink jet printer) using the environment-friendly ink jet recording head 50 and improve the resolution of the device using the ink jet recording head 50.

  2.3. In the above description, an ink jet recording head that discharges ink has been described as an example. However, the present embodiment is intended for liquid ejecting heads and liquid ejecting apparatuses that use piezoelectric elements. Examples of the liquid ejecting head include a recording head used in an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (surface emitting display). Examples thereof include an electrode material ejecting head used in manufacturing, a bioorganic matter ejecting head used in biochip manufacturing, and the like.

  3. Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are included in the scope of the present invention.

  For example, the piezoelectric element according to the present invention is not only applied to the above-described devices, but also various devices (for example, piezoelectric pumps, surface acoustic wave elements, frequency filters, thin film piezoelectric resonators, oscillators, electronic circuits, electronic devices) Etc.).

Sectional drawing which shows the piezoelectric element which concerns on 1st Embodiment. Sectional drawing which shows typically one manufacturing process of the piezoelectric element which concerns on 1st Embodiment. Sectional drawing which shows typically one manufacturing process of the piezoelectric element which concerns on 1st Embodiment. 1 is a schematic configuration diagram of an ink jet recording head. FIG. 2 is an exploded perspective view of an ink jet recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric element, 2 board | substrate, 3 elastic film, 4 lower electrode, 5 1st piezoelectric film, 6 2nd piezoelectric film, 7 upper electrode, 8 material layer, 50 inkjet recording head, 51 nozzle plate, 52 ink chamber Substrate, 54 Piezoelectric part, 55 Elastic film, 56 Housing, 57 Head body, 521 Cavity

Claims (11)

A substrate,
And a piezoelectric film that is formed above the substrate and includes at least a piezoelectric body made of (Na, K, Li) NbO ₃ . In claim 1,
The piezoelectric body is a piezoelectric element represented by the following formula.
_{(1-x) (Na,} K) NbO 3 -xLiNbO 3
(However, 0.05 ≦ x ≦ 0.06) In claim 2,
x is a value at a phase boundary of the crystal structure of the piezoelectric body. In any one of Claims 1-3,
The piezoelectric element includes a cerium oxide. In claim 4,
The piezoelectric element, wherein an addition amount of cerium oxide in the piezoelectric body is 0.2% by weight or more and 1% by weight or less. In any one of Claims 1-5,
A first conductive layer formed above the substrate and below the piezoelectric film;
And a second conductive layer formed above the piezoelectric film. Forming a first piezoelectric film including a piezoelectric material represented by the following formula (1) above the substrate;
Laminating a material layer for forming a piezoelectric body represented by the following formula (2) above the first piezoelectric film;
Forming a second piezoelectric film including at least a piezoelectric material represented by the following formula (3) by performing a heat treatment on the first piezoelectric film and the material layer: .
(Na, K) NbO ₃ (1)
(1-x) (Na, K) NbO ₃ —xLiNbO ₃ (2)
(However, 0.08 ≦ x ≦ 0.10)
(1-x) (Na, K) NbO ₃ —xLiNbO ₃ Formula (3)
(However, 0.05 ≦ x ≦ 0.06) In claim 7,
The method of manufacturing a piezoelectric element, wherein the piezoelectric body represented by the formulas (1) to (3) includes cerium oxide. In claim 8,
The addition amount of cerium oxide in the piezoelectric body represented by the formula (1) is 0.2 wt% or more and 1 wt% or less,
The amount of cerium oxide added in the piezoelectric body represented by the formula (2) is 0.2 wt% or more and 1 wt% or less,
The method for manufacturing a piezoelectric element, wherein an addition amount of cerium oxide in the piezoelectric body represented by the formula (3) is 0.2% by weight or more and 1% by weight or less.   A piezoelectric actuator comprising the piezoelectric element according to claim 1.   An ink jet recording head comprising the piezoelectric element according to claim 1.

Images