Piezoelectric body, piezoelectric element, and liquid ejection head

Abstract

To provide a piezoelectric material which does not include an intermediate layer and is hard to be cracked.SOLUTION: The present invention relates to a piezoelectric material containing kalium, natrium and niobium and has a perovskite structure. A Raman shift of a peak belonging to A1g obtained by performing Raman spectroscopic analysis on a plurality of measurement regions is 400 cm-1 or more and 700 cm-1 or less. A difference between a maximum value and a minimum value of the Raman shift among the peaks in the plurality of measurement regions is 11.0 cm-1 or less.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a piezoelectric body, a piezoelectric element, and a liquid ejection head. [Background technology]

[0002] The piezoelectric element used in the liquid ejection head is a piezoelectric body made of a piezoelectric material with electromechanical conversion function, sandwiched between two electrodes. Potassium sodium niobate-based piezoelectric materials are known as such piezoelectric materials.

[0003] Potassium sodium niobate-based piezoelectric materials have the problem that cracks tend to occur during manufacturing, which is particularly problematic when forming a piezoelectric material with a large thickness.

[0004] For example, Patent Document 1 describes a piezoelectric element that can alleviate residual stress in the piezoelectric layers and suppress the occurrence of cracks by providing an intermediate layer formed by vapor deposition between first and second piezoelectric layers formed by CSD. Specifically, in an example of Patent Document 1, a composite oxide having a composition as a mixed crystal of KNN and BFO is used for the first and second piezoelectric layers, and Pt is used for the intermediate layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-139923 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the piezoelectric element described in Patent Document 1, an intermediate layer made of a different material from the first and second piezoelectric layers is provided between the first and second piezoelectric layers. Therefore, the crystal structure of the second piezoelectric layer may vary depending on the plane orientation, crystal grain size, and precipitates on the surface of the intermediate layer. This may result in variations in the crystal structure of the second piezoelectric layer in the in-plane direction. Variations in the crystal structure of the second piezoelectric layer result in variations in the piezoelectric properties of the piezoelectric element, resulting in a loss of quality.

[0007] Therefore, there is a demand for a potassium sodium niobate-based piezoelectric material that does not have an intermediate layer and is less susceptible to cracking. [Means for solving the problem]

[0008] One aspect of the piezoelectric body according to the present invention is containing potassium, sodium, and niobium, It has a perovskite structure, A obtained by Raman spectroscopy on multiple measurement areas 1g The Raman shift of the peak assigned to is 400 cm -1 More than 700cm -1 is as follows: The difference between the maximum and minimum Raman shifts of the peaks in the plurality of measurement regions is 11.0 cm -1 The following is the result.

[0009] One aspect of the piezoelectric element according to the present invention is a first electrode provided on a substrate; The piezoelectric body provided on the first electrode; a second electrode provided on the piezoelectric body; Includes.

[0010] One aspect of the liquid ejection head according to the present invention is The piezoelectric element; the substrate; a nozzle plate provided with nozzle holes; Including, the base body has a flow path forming substrate provided with a pressure generating chamber whose volume changes due to the piezoelectric element, The nozzle hole communicates with the pressure generating chamber. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a piezoelectric element according to an embodiment of the present invention. [Figure 2] FIG. 10 is a cross-sectional view schematically showing a piezoelectric element according to a modified example of the embodiment. [Figure 3] FIG. 1 is an exploded perspective view schematically showing a liquid ejection head according to an embodiment of the present invention. [Figure 4] FIG. 1 is a plan view schematically showing a liquid ejection head according to an embodiment of the present invention. [Figure 5] FIG. 1 is a cross-sectional view schematically showing a liquid ejection head according to an embodiment of the present invention. [Figure 6] FIG. 1 is a perspective view schematically illustrating a printer according to an embodiment of the present invention. [Figure 7] Graph showing the Raman shift of the peak attributed to A1g in Example 1. [Figure 8] Graph showing the Raman shift of the peak attributed to A1g in Comparative Example 1. [Figure 9] FIG. 1 is a diagram for explaining a unit cell of a tetragonal crystal system. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0013] 1. Piezoelectric element Configuration First, the piezoelectric element according to this embodiment will be described with reference to the drawings. Fig. 1 is a cross-sectional view that schematically shows a piezoelectric element 100 according to this embodiment.

[0014] 1, the piezoelectric element 100 includes a first electrode 10, a piezoelectric body 20, and a second electrode 30. The piezoelectric element 100 is provided on a base body 2.

[0015] The base 2 is, for example, a flat plate made of a semiconductor, an insulator, or the like. The base 2 may be a single layer or a laminate of multiple layers. The internal structure of the base 2 is not limited as long as the upper surface has a flat shape, and the base 2 may have a structure in which a space or the like is formed inside.

[0016] The base 2 may include a flexible diaphragm that is deformed by the operation of the piezoelectric body 20. The diaphragm is, for example, a silicon oxide layer, a zirconium oxide layer, or a laminate in which a zirconium oxide layer is provided on a silicon oxide layer.

[0017] The first electrode 10 is provided on the base 2. The first electrode 10 is provided between the base 2 and the piezoelectric body 20. The first electrode 10 has, for example, a layered shape. The thickness of the first electrode 10 is, for example, 3 nm or more and 300 nm or less. The first electrode 10 is, for example, a metal layer such as a platinum layer, an iridium layer, a titanium layer, or a ruthenium layer, a conductive oxide layer of these metal layers, a lanthanum nickelate (LaNiO3:LNO) layer, or a strontium ruthenate (SrRuO3:SRO) layer. The first electrode 10 may have a structure in which a plurality of the layers exemplified above are stacked.

[0018] The first electrode 10 is one of the electrodes for applying a voltage to the piezoelectric body 20. The first electrode 10 is a lower electrode provided below the piezoelectric body 20.

[0019] Although not shown, an adhesion layer may be provided between the base 2 and the first electrode 10 in order to improve adhesion between the base 2 and the first electrode 10. The adhesion layer is, for example, a titanium layer or a titanium oxide layer.

[0020] The piezoelectric body 20 is provided on the first electrode 10. The piezoelectric body 20 is provided between the first electrode 10 and the second electrode 30. Although not shown, the piezoelectric body 20 may be provided on the first electrode 10 and on the base 2. The piezoelectric body 20 has a layered shape. The piezoelectric body 20 is configured by stacking multiple crystal layers. The thickness of the piezoelectric body 20 is, for example, 100 nm or more and 3 μm or less, preferably 200 nm or more and 2 μm or less. The piezoelectric body 20 can be deformed by applying a voltage between the first electrode 10 and the second electrode 30.

[0021] The piezoelectric body 20 has a perovskite structure. The crystal structure of the piezoelectric body 20 is, for example, a tetragonal system. The piezoelectric body 20 is, for example, a potassium sodium niobate (KNN) layer containing potassium (K), sodium (Na), and niobium (Nb). The piezoelectric body 20 may also be a KNN layer to which an additive such as manganese (Mn) is added.

[0022] The piezoelectric body 20 is, for example, preferentially oriented in the (100) plane. "Preferential orientation" means that 70% or more, preferably 80% or more, of the crystals are oriented in a predetermined crystal plane. "Preferential orientation in the (100) plane" includes a case where all of the crystals in the piezoelectric body 20 are oriented in the (100) plane, and a case where 70% or more, preferably 80% or more, of the crystals are oriented in the (100) plane.

[0023] Piezoelectric body 20 does not have an intermediate layer. An "intermediate layer" refers to a layer whose main component is made of a material different from the main component of the portions of piezoelectric body 20 other than the intermediate layer. For example, if the main component of piezoelectric body 20 is KNN, the main component of the intermediate layer is not KNN. "Main component" refers to a material that accounts for 50% by mass or more.

[0024] The second electrode 30 is provided on the piezoelectric body 20. Although not shown, the second electrode 30 may be further provided on the side surface of the piezoelectric body 20 and on the base body 2, as long as it is electrically separated from the first electrode 10.

[0025] The second electrode 30 has a layered shape, for example. The thickness of the second electrode 30 is, for example, 3 nm or more and 300 nm or less. The second electrode 30 is, for example, a metal layer such as an iridium layer, a platinum layer, a titanium layer, or a ruthenium layer, a conductive oxide layer of these metals, a lanthanum nickelate layer, or a strontium ruthenate layer. The second electrode 30 may have a structure in which a plurality of the layers exemplified above are stacked.

[0026] The second electrode 30 is the other electrode for applying a voltage to the piezoelectric body 20. The second electrode 30 is an upper electrode provided on the piezoelectric body 20.

[0027] 1.2. Raman spectroscopy A obtained by performing Raman spectroscopy on a plurality of measurement areas of the piezoelectric body 20 1g The Raman shift of the peak assigned to is 400 cm -1 More than 700cm -1 and preferably 500 cm -1 More than 650cm -1 More preferably, it is 600 cm or less. -1 More than 610cm -1 less than or equal to 601 cm -1 Over 607cm -1 The measurement region measured by Raman spectroscopy is, for example, a region on the upper surface of the piezoelectric body 20. The plurality of measurement regions measured by Raman spectroscopy may be arranged linearly in a plan view.

[0028] The difference Δ between the maximum and minimum values ​​of the Raman shift among the peaks in the plurality of measurement regions of the piezoelectric body 20 was 11.0 cm -1 less than 7.0 cm, preferably -1 and more preferably 5.0 cm or less. -1 less than or equal to, and even more preferably, 4.5 cm -1 The difference Δ is 0.0 cm. -1 It can be larger than 0.0cm -1 may be.

[0029] The standard deviation σ of the Raman shifts of the peaks in the plurality of measurement regions of the piezoelectric body 20 is, for example, 2 cm -1 less than 1.5cm, preferably -1 and more preferably 1.0 cm or less. -1 The standard deviation σ is 0.0 cm -1 It can be larger than 0.0cm -1 may be.

[0030] 1.3. Effects The piezoelectric body 20 contains potassium, sodium, and niobium, has a perovskite structure, and A 1g The Raman shift of the peak assigned to is 400 cm -1 More than 700cm -1 The difference Δ between the maximum and minimum Raman shifts of the peaks in the multiple measurement regions is 11.0 cm or less. -1 Therefore, in the piezoelectric body 20, as shown in the examples and comparative examples described later, the difference Δ is 11.0 cm -1 Cracks are less likely to occur than when the thickness is larger.

[0031] Furthermore, the piezoelectric body 20 does not have an intermediate layer. Therefore, it is possible to suppress variations in the piezoelectric characteristics in the in-plane direction of the piezoelectric body due to the intermediate layer in the piezoelectric body 20. The "in-plane direction" refers to the direction perpendicular to the thickness direction of the piezoelectric body 20.

[0032] As described above, the piezoelectric body 20 does not have an intermediate layer and is therefore less susceptible to cracks.

[0033] The piezoelectric body 20 may be preferentially oriented in the (100) plane. A piezoelectric body 20 preferentially oriented in the (100) plane is less susceptible to cracking than a piezoelectric body preferentially oriented in a plane other than the (100) plane. This allows the thickness of the piezoelectric body 20 to be increased.

[0034] For the piezoelectric body 20, the difference Δ is 5.0 cm -1 The difference Δ may be 5.0 cm or less.-1 The following piezoelectric element 20 has a difference Δ of 5.0 cm -1 Cracks are less likely to occur compared to larger piezoelectric materials.

[0035] 2. Manufacturing method of piezoelectric element Next, a method for manufacturing the piezoelectric element 100 according to this embodiment will be described with reference to the drawings.

[0036] As shown in Figure 1, a base 2 is prepared. Specifically, a silicon oxide layer is formed by thermally oxidizing a silicon substrate. Next, a zirconium layer is formed on the silicon oxide layer by a method such as sputtering, and the zirconium layer is then thermally oxidized to form a zirconium oxide layer. This allows the formation of a diaphragm consisting of a silicon oxide layer and a zirconium oxide layer. Through the above steps, the base 2 can be prepared.

[0037] Next, the first electrode 10 is formed on the substrate 2. In order to improve the adhesion between the substrate 2 and the first electrode 10, an adhesion layer such as a titanium layer or a titanium oxide layer may be formed between the substrate 2 and the first electrode 10. The first electrode 10 is formed by, for example, sputtering or vacuum deposition. Next, the first electrode 10 is patterned by, for example, photolithography and etching.

[0038] Next, the piezoelectric body 20 is formed on the first electrode 10. The piezoelectric body 20 is formed by a sol-gel method or a CSD (Chemical Solution Deposition) method such as MOD (Metal Organic Deposition). A method for forming the piezoelectric body 20 will be described below.

[0039] First, a precursor solution is prepared by dissolving or dispersing, for example, a metal complex containing potassium, a metal complex containing sodium, a metal complex containing niobium, and a metal complex containing manganese in an organic solvent.

[0040] Examples of metal complexes containing potassium include potassium 2-ethylhexanoate and potassium acetate. Examples of metal complexes containing sodium include sodium 2-ethylhexanoate and sodium acetate. Examples of metal complexes containing niobium include niobium 2-ethylhexanoate, pentaethoxyniobium, and pentabutoxyniobium. Examples of metal complexes containing manganese include manganese 2-ethylhexanoate. Two or more metal complexes may be used in combination. For example, potassium 2-ethylhexanoate and potassium acetate may be used in combination as metal complexes containing potassium.

[0041] Examples of the solvent include propanol, butanol, pentanol, hexanol, octanol, ethylene glycol, propylene glycol, octane, decane, cyclohexane, xylene, toluene, tetrahydrofuran, acetic acid, octylic acid, 2-n-butoxyethanol, and mixed solvents thereof.

[0042] Next, the prepared precursor solution is applied to the first electrode 10 by spin coating or the like to form a precursor layer. Next, the precursor layer is heated, for example, at 130°C to 250°C and dried for a certain period of time, and the dried precursor layer is further degreased by heating, for example, at 300°C to 450°C and holding for a certain period of time. Next, the degreased precursor layer is crystallized by firing, for example, at 550°C to 800°C, to form a crystal layer.

[0043] The above series of steps, from applying the precursor solution to firing the precursor layer, is then repeated multiple times. This allows the piezoelectric body 20, which is made up of multiple crystal layers, to be formed. Next, the piezoelectric body 20 is patterned. The patterning is performed by, for example, photolithography and etching.

[0044] The heating device used for drying and degreasing the precursor layer is, for example, a hot plate, and the heating device used for baking the precursor layer is, for example, an RTA (Rapid Thermal Annealing) device.

[0045] Next, the second electrode 30 is formed on the piezoelectric body 20. The second electrode 30 is formed by, for example, a sputtering method or a vacuum deposition method. Next, the second electrode 30 is patterned. The patterning is performed by, for example, photolithography and etching.

[0046] Through the above steps, the piezoelectric element 100 can be manufactured.

[0047] The patterning of the second electrode 30 and the patterning of the piezoelectric body 20 may be performed in the same step. Furthermore, the first crystal layer of the piezoelectric body 20 and the first electrode 10 may be patterned in the same step.

[0048] 3. Modified Piezoelectric Elements Next, a piezoelectric element according to a modified example of this embodiment will be described with reference to the drawings. Fig. 2 is a cross-sectional view schematically showing a piezoelectric element 110 according to a modified example of this embodiment. Hereinafter, in the piezoelectric element 110 according to this modified example of this embodiment, components having the same functions as the components of the piezoelectric element 100 according to this embodiment described above will be given the same reference numerals, and detailed description thereof will be omitted.

[0049] As shown in FIG. 2, the piezoelectric element 110 differs from the above-described piezoelectric element 100 in that it includes a seed layer 40 .

[0050] The seed layer 40 is provided between the first electrode 10 and the piezoelectric body 20. The seed layer 40 is provided on the first electrode 10. In the illustrated example, the seed layer 40 is also provided on the base 2. Although not illustrated, the seed layer 40 may be provided only on the first electrode 10. The seed layer 40 is, for example, an oxide containing bismuth (Bi), iron (Fe), titanium (Ti), lead (Pb), etc. The seed layer 40 may also be bismuth ferrate titanate with lead added. The seed layer 40 is a layer that controls the orientation of the piezoelectric body 20.

[0051] The seed layer 40 is formed by, for example, a sputtering method, a vacuum deposition method, a solution method, etc. The seed layer 40 may be patterned in the same process as the piezoelectric body 20 is patterned.

[0052] The piezoelectric element 110 includes a seed layer 40 provided between the first electrode 10 and the piezoelectric body 20. Therefore, in the piezoelectric element 110, the orientation of the piezoelectric body 20 can be improved compared to, for example, a case where the seed layer 40 is not provided. Specifically, the orientation of the (100) plane of the piezoelectric body 20 can be improved.

[0053] 4. Liquid ejection head Next, the liquid ejection head according to this embodiment will be described with reference to the drawings. Fig. 3 is an exploded perspective view that schematically shows the liquid ejection head 200 according to this embodiment. Fig. 4 is a plan view that schematically shows the liquid ejection head 200 according to this embodiment. Fig. 5 is a cross-sectional view taken along line VV in Fig. 4 that schematically shows the liquid ejection head 200 according to this embodiment. Note that Figs. 3 to 5 illustrate an X-axis, a Y-axis, and a Z-axis as three mutually orthogonal axes. Furthermore, Figs. 3 and 5 illustrate a simplified version of the piezoelectric element 100.

[0054] 3 to 5, the liquid ejection head 200 includes, for example, a base 2, a piezoelectric element 100, a nozzle plate 220, a protective substrate 240, a circuit board 250, and a compliance substrate 260. The base 2 has a flow path forming substrate 210 and a vibration plate 230. For convenience, the circuit board 250 is not shown in FIG.

[0055] The flow path forming substrate 210 is, for example, a silicon substrate. The flow path forming substrate 210 is provided with pressure generating chambers 211. The pressure generating chambers 211 are partitioned by a plurality of partition walls 212. The volume of the pressure generating chambers 211 changes depending on the piezoelectric elements 100.

[0056] A first communication passage 213 and a second communication passage 214 are provided at the end of the pressure generating chamber 211 in the +X axis direction of the flow path forming substrate 210. The first communication passage 213 is configured so that its opening area is reduced by narrowing the end of the pressure generating chamber 211 in the +X axis direction from the Y axis direction. The width of the second communication passage 214 in the Y axis direction is, for example, the same as the width of the pressure generating chamber 211 in the Y axis direction. A third communication passage 215 that communicates with the plurality of second communication passages 214 is provided at the +X axis direction of the second communication passage 214. The third communication passage 215 forms a part of a manifold 216. The manifold 216 serves as a common liquid chamber for each pressure generating chamber 211. In this way, the flow path The formation substrate 210 is provided with a supply flow path 217 consisting of a first communication path 213, a second communication path 214, and a third communication path 215, and a pressure generating chamber 211. The supply flow path 217 communicates with the pressure generating chamber 211 and supplies liquid to the pressure generating chamber 211.

[0057] The nozzle plate 220 is provided on one surface of the flow path forming substrate 210. The material of the nozzle plate 220 is, for example, SUS (Steel Use Stainless). The nozzle plate 220 is joined to the flow path forming substrate 210 by, for example, an adhesive or a heat-sealed film. The nozzle plate 220 has a plurality of nozzle holes 222 formed along the Y axis. The nozzle holes 222 communicate with the pressure generating chambers 211 and eject liquid.

[0058] The vibration plate 230 is provided on the other surface of the flow path forming substrate 210. The vibration plate 230 is composed of, for example, a silicon oxide layer 232 provided on the flow path forming substrate 210 and a zirconium oxide layer 234 provided on the silicon oxide layer 232.

[0059] The piezoelectric element 100 is provided, for example, on the vibration plate 230. A plurality of piezoelectric elements 100 are provided. The number of piezoelectric elements 100 is not particularly limited.

[0060] In the liquid ejection head 200, the vibration plate 230 and the first electrode 10 are displaced by deformation of the piezoelectric body 20, which has electromechanical transduction characteristics. That is, in the liquid ejection head 200, the vibration plate 230 and the first electrode 10 essentially function as a vibration plate.

[0061] The first electrode 10 is configured as an independent individual electrode for each pressure generating chamber 211. The width of the first electrode 10 in the Y-axis direction is narrower than the width of the pressure generating chamber 211 in the Y-axis direction. The length of the first electrode 10 in the X-axis direction is longer than the length of the pressure generating chamber 211 in the X-axis direction. In the X-axis direction, both ends of the first electrode 10 are positioned with both ends of the pressure generating chamber 211 between them. A lead electrode 202 is connected to the end of the first electrode 10 in the -X-axis direction.

[0062] The width of the piezoelectric body 20 in the Y-axis direction is, for example, wider than the width of the first electrode 10 in the Y-axis direction. The length of the piezoelectric body 20 in the X-axis direction is, for example, longer than the length of the pressure generating chamber 211 in the X-axis direction. The end of the first electrode 10 in the +X-axis direction is located, for example, between the end of the piezoelectric body 20 in the +X-axis direction and the end of the pressure generating chamber 211 in the +X-axis direction. The end of the first electrode 10 in the +X-axis direction is covered by the piezoelectric body 20. On the other hand, the end of the piezoelectric body 20 in the -X-axis direction is located, for example, between the end of the first electrode 10 in the -X-axis direction and the end of the pressure generating chamber 211 in the +X-axis direction. The end of the first electrode 10 in the -X-axis direction is not covered by the piezoelectric body 20.

[0063] The second electrode 30 is provided, for example, continuously on the piezoelectric body 20 and the vibration plate 230. The second electrode 30 is configured as a common electrode shared by a plurality of piezoelectric elements 100.

[0064] The protective substrate 240 is bonded to the diaphragm 230 with an adhesive 203. A through hole 242 is provided in the protective substrate 240. In the example shown, the through hole 242 penetrates the protective substrate 240 in the Z-axis direction and communicates with the third communication passage 215. The through hole 242 and the third communication passage 215 form a manifold 216 that serves as a common liquid chamber for each pressure generating chamber 211. Furthermore, the protective substrate 240 is provided with a through hole 244 that penetrates the protective substrate 240 in the Z-axis direction. An end of the lead electrode 202 is located in the through hole 244.

[0065] An opening 246 is provided in the protection substrate 240. The opening 246 is a space that does not impede the driving of the piezoelectric element 100. The opening 246 may or may not be sealed.

[0066] The circuit board 250 is provided on the protection board 240. The circuit board 250 has a piezoelectric element It includes a semiconductor integrated circuit (IC) for driving the element 100. The circuit board 250 and the lead electrodes 202 are electrically connected via connection wiring 204.

[0067] The compliance substrate 260 is provided on the protection substrate 240. The compliance substrate 260 has a sealing layer 262 provided on the protection substrate 240, and a fixing plate 264 provided on the sealing layer 262. The sealing layer 262 is a layer for sealing the manifold 216. The sealing layer 262 has, for example, flexibility. A through-hole 266 is provided in the fixing plate 264. The through-hole 266 passes through the fixing plate 264 in the Z-axis direction. The through-hole 266 is provided at a position overlapping with the manifold 216 when viewed from the Z-axis direction.

[0068] 5. Printer Next, a printer according to this embodiment will be described with reference to the drawings. Figure 6 is a perspective view that schematically shows a printer 300 according to this embodiment.

[0069] The printer 300 is an inkjet printer. As shown in FIG. 6, the printer 300 includes a head unit 310. The head unit 310 has, for example, liquid ejection heads 200. There is no particular limit to the number of liquid ejection heads 200. Cartridges 312 and 314, which constitute a supply means, are detachably provided on the head unit 310. A carriage 316 carrying the head unit 310 is axially movable on a carriage shaft 322 attached to the device main body 320, and ejects liquid supplied from the liquid supply means.

[0070] Here, a liquid refers to any material in a liquid phase, including liquid-state materials such as sols and gels. Liquids not only refer to a single state of matter, but also to particles of functional materials made of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent. Representative examples of liquids include inks and liquid crystal emulsifiers. Ink encompasses various liquid compositions, such as general water-based inks and oil-based inks, as well as gel inks and hot-melt inks.

[0071] In the printer 300, the driving force of a drive motor 330 is transmitted to a carriage 316 via multiple gears (not shown) and a timing belt 332, causing the carriage 316, which carries the head unit 310, to move along a carriage shaft 322. Meanwhile, the device main body 320 is provided with a transport roller 340 as a transport mechanism that moves a sheet S, which is a recording medium such as paper, relative to the liquid ejection head 200. The transport mechanism that transports the sheet S is not limited to a transport roller, and may be a belt, a drum, or the like.

[0072] The printer 300 includes a printer controller 350 as a control unit that controls the liquid ejection head 200 and the transport roller 340. The printer controller 350 is electrically connected to a circuit board 250 of the liquid ejection head 200. The printer controller 350 includes, for example, a random access memory (RAM) that temporarily stores various data, a read only memory (ROM) that stores control programs and the like, a central processing unit (CPU), and a drive signal generating circuit that generates drive signals to be supplied to the liquid ejection head 200.

[0073] The piezoelectric element 100 can be used in a wide range of applications, not limited to liquid ejection heads and printers. The piezoelectric element 100 is suitably used as a piezoelectric actuator for, for example, ultrasonic motors, vibration-type dust removal devices, piezoelectric transformers, piezoelectric speakers, piezoelectric pumps, and pressure-electricity conversion devices. The piezoelectric element 100 can also be used in, for example, ultrasonic detectors, angular velocity sensors, acceleration sensors, vibration sensors, tilt sensors, pressure sensors, collision sensors, human sensors, infrared sensors, terahertz sensors, heat detection sensors, pyroelectric sensors, and the like. The piezoelectric element 100 is preferably used as a piezoelectric sensor element such as a piezoelectric sensor, a piezoelectric sensor, etc. The piezoelectric element 100 is also preferably used as a ferroelectric element such as a ferroelectric memory (FeRAM), a ferroelectric transistor (FeFET), a ferroelectric arithmetic circuit (FeLogic), a ferroelectric capacitor, etc. The piezoelectric element 100 is also preferably used as a voltage-controlled optical element such as a wavelength converter, an optical waveguide, an optical path modulator, a refractive index control element, an electronic shutter mechanism, etc.

[0074] 6. Examples and Comparative Examples 6.1. Sample preparation Example 1 In Example 1, first, a silicon dioxide layer was formed on the silicon substrate by thermally oxidizing the silicon substrate. Next, a zirconium layer was formed on the silicon dioxide layer by sputtering, and the zirconium layer was thermally oxidized to form a zirconium oxide layer. Next, a first electrode was formed on the zirconium oxide layer by sputtering. The material of the first electrode was platinum.

[0075] Next, a solution containing potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, niobium 2-ethylhexanoate, and manganese 2-ethylhexanoate (K 0.5 Na 0.5 ) 1.04 (Nb 0.995 Mn 0.05 The solution was mixed to obtain 03, and applied to the first electrode by spin coating. It was then dried at 180°C, degreased at 380°C, and heated at 700°C for 3 minutes using an RTA device. The process from applying the solution to the heating was repeated until cracks appeared in the piezoelectric body. The thickness of each of the multiple crystal layers constituting the piezoelectric body was set to 30 nm.

[0076] 6.1.2. Comparative Example 1 In Comparative Example 1, the thickness of each of the plurality of crystal layers constituting the piezoelectric body was set to 75 nm, and other than this, the piezoelectric body was fabricated in the same manner as in Example 1 described above.

[0077] 6.2. Checking for cracks In Example 1 and Comparative Example 1, the presence or absence of cracks was checked using a phase-contrast microscope each time a crystal layer was formed. The phase-contrast microscope used was an "OPTIPHOT200" manufactured by Nikon Corporation. The eyepiece was set to 10x magnification, and the objective lens was set to 100x magnification.

[0078] In Example 1, cracks were observed when 35 crystal layers were stacked. On the other hand, in Comparative Example 1, cracks were observed when 10 crystal layers were stacked. When cracks were observed, stacking of the crystal layers was stopped.

[0079] 6.3. Raman spectroscopy The piezoelectric materials of Example 1 and Comparative Example 1, in which the above cracks were confirmed, were subjected to Raman spectroscopic analysis. For the Raman spectroscopic analysis, a Raman spectrometer "Nanofinder 30" manufactured by Tokyo Instruments Inc. was used. The excitation wavelength was 325 nm, the focal length was 52 cm, and the diffraction grating was 3600 lines / mm. The CCD detector used was a "DU420-BU" manufactured by ANDOR. 45 points were measured linearly with a measurement step of 0.1 μm. The measurement time for one measurement area was 20 seconds.

[0080] 600cm obtained by Raman spectroscopy -1 The nearby peaks were fitted with Lorentzian fitting (see Ruio-Macros, Del Campo, and Fernandez J. Appl. Phys. 113, 187215 (2013)). g The peaks assigned to A 1g The peaks assigned to A in Example 1 were separated. 1g 8 is a graph showing the Raman shift of the peaks attributable to A in Comparative Example 1. 1g The graph shows the Raman shift of the peaks assigned to The horizontal axis in Figures 7 and 8 indicates the distance from the first measurement area, assuming that the position of the first measurement area is zero. The vertical axis in Figures 7 and 8 indicates the Raman shift in the measurement area.

[0081] As shown in FIGS. 7 and 8, Example 1 had smaller variations in Raman shifts in a plurality of measurement regions than Comparative Example 1.

[0082] In Example 1, the maximum value of the Raman shift in multiple measurement regions was 606.2 cm -1 The minimum value was 601.8 cm -1 The difference between the maximum and minimum values ​​was 4.4 cm. -1 The standard deviation was 0.99 cm -1 It was.

[0083] In Comparative Example 1, the maximum value of the Raman shift in multiple measurement regions was 608.1 cm -1 The minimum value was 596.5 cm -1 The difference between the maximum and minimum values ​​was 11.6 cm. -1 The standard deviation was 2.64 cm. -1 It was.

[0084] From this experiment, it was found that the smaller the difference between the maximum and minimum values ​​of the Raman shift in multiple measurement regions of the piezoelectric body, the less likely cracks are to occur.

[0085] Here, FIG. 9 is a diagram for explaining the unit cell of a tetragonal system. -1 Nearby A 1g The peaks attributable to the shorter the c-axis of the unit cell, i.e., the closer it is to a cubic system, the lower the frequency shifts, and the longer the c-axis, the higher the frequency shifts. If the c-axis length varies significantly, strong stress is applied at the boundary surface between adjacent unit cells, and properties such as the linear expansion coefficient also differ, which is thought to result in poor crack resistance. Therefore, it is expected that the thickness at which cracks occur was small in Comparative Example 1. On the other hand, it is expected that the thickness at which cracks occur was large in Example 1 because the variation in the c-axis length was small.

[0086] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0087] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0088] The following can be derived from the above-described embodiment and modifications.

[0089] One aspect of the piezoelectric body is containing potassium, sodium, and niobium, It has a perovskite structure, A obtained by Raman spectroscopy on multiple measurement areas 1g The Raman shift of the peak assigned to is 400 cm -1 More than 700cm -1 is as follows: The difference between the maximum and minimum Raman shifts of the peaks in the plurality of measurement regions is 11.0 cm -1 The following is the result.

[0090] This piezoelectric body does not have an intermediate layer and is therefore less susceptible to cracks.

[0091] In one embodiment of the piezoelectric body, The (100) plane may be preferentially oriented.

[0092] This piezoelectric element allows the thickness of the piezoelectric element to be increased.

[0093] In one embodiment of the piezoelectric body, The difference is 5.0 cm -1 It may be the following:

[0094] This piezoelectric body is less susceptible to cracks.

[0095] One aspect of the piezoelectric element is a first electrode provided on a substrate; The piezoelectric body provided on the first electrode; a second electrode provided on the piezoelectric body; Includes.

[0096] In one embodiment of the piezoelectric element, The piezoelectric element may include a seed layer provided between the first electrode and the piezoelectric body.

[0097] This piezoelectric element can improve the orientation of the piezoelectric body.

[0098] One aspect of the liquid ejection head is The piezoelectric element; the substrate; a nozzle plate provided with nozzle holes; Including, the base body has a flow path forming substrate provided with a pressure generating chamber whose volume changes due to the piezoelectric element, The nozzle hole communicates with the pressure generating chamber. [Explanation of symbols]

[0099] 2...base, 10...first electrode, 20...piezoelectric body, 30...second electrode, 40...seed layer, 100, 110...piezoelectric element, 200...liquid ejection head, 202...lead electrode, 203...adhesive, 204...connection wiring, 210...flow path forming substrate, 211...pressure generating chamber, 212...partition wall, 213...first communication path, 214...second communication path, 215...third communication path, 216...manifold, 217...supply path, 220...nozzle plate, 222...nozzle hole, 230...vibration plate, 232...silicon oxide layer, 2 34...zirconium oxide layer, 240...protective substrate, 242, 244...through hole, 246...opening, 250...circuit board, 260...compliance substrate, 262...sealing layer, 264...fixing plate, 266...through hole, 300...printer, 310...head unit, 312, 314...cartridge, 316...carriage, 320...device main body, 322...carriage shaft, 330...drive motor, 332...timing belt, 340...conveyor roller, 350...printer controller

Claims

1. containing potassium, sodium, and niobium, It has a perovskite structure, The Raman shift of the peak attributed to A1g obtained by Raman spectroscopy on multiple measurement areas was 600 cm －１ 610cm or more －１ is as follows: The difference between the maximum and minimum Raman shifts of the peaks in the plurality of measurement regions is 11.0 cm －１ The following is a piezoelectric material.

2. In claim 1, A piezoelectric material that is preferentially oriented in the (100) plane.

3. In claim 1 or 2, The difference is 5.0 cm －１ The following is a piezoelectric material.

4. In any one of claims 1 to 3, A piezoelectric body, wherein the standard deviation of the Raman shifts of the peaks in the plurality of measurement regions is 2 cm −1 or less.

5. a first electrode provided on a substrate; a piezoelectric body according to claim 1 provided on the first electrode; a second electrode provided on the piezoelectric body; A piezoelectric element comprising:

6. In claim 5, A piezoelectric element including a seed layer provided between the first electrode and the piezoelectric body.

7. The piezoelectric element according to claim 5 or 6, the substrate; a nozzle plate provided with nozzle holes; Including, the base body has a flow path forming substrate provided with a pressure generating chamber whose volume changes due to the piezoelectric element, The nozzle hole is in communication with the pressure generating chamber.

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