JP5121186B2 - Piezoelectric body, piezoelectric element, liquid discharge head, and liquid discharge apparatus - Google Patents

Description

The present invention relates to a piezoelectric body, a piezoelectric element, a liquid ejection head, and a liquid ejection apparatus using these used in a liquid ejection apparatus . More specifically, the present invention relates to a large-area, high-density piezoelectric element, a liquid discharge head, and a liquid discharge apparatus using these.

  In an ink jet printer, higher resolution, higher speed printing, and longer head are required. Therefore, it is required to realize a multi-nozzle head structure with a miniaturized head. In order to reduce the size of the liquid discharge head, it is necessary to reduce the size of the piezoelectric element for discharging the liquid. Further, in order to reduce the size of the piezoelectric element, the driving capability is reduced even if the size is reduced. A piezoelectric body having a high piezoelectric constant is required. For this reason, in the case of a piezoelectric body using a piezoelectric film, a film having excellent crystallinity, that is, a film in which the crystallinity of highly oriented crystals is controlled is required as the piezoelectric film. In order to make the piezoelectric film highly oriented crystal, the layer directly under the piezoelectric film has higher crystallinity, and the piezoelectric film and the layer immediately below it have a good lattice matching. It is preferable.

  In addition, the piezoelectric film and the layer immediately below the film tend to peel off due to stress applied to the interface due to the thinning of the piezoelectric film, and have good adhesion to the piezoelectric film to suppress this film peeling. There is also a request.

Conventionally, a piezoelectric film used for a piezoelectric element has a PZT obtained by forming a green sheet by molding a PbO, ZrO ₂ and TiO ₂ powder paste into a sheet and then sintering the sheet. A piezoelectric material is used (Patent Document 1).

  In addition, as a piezoelectric material, there is a relaxor material having very high piezoelectric characteristics as compared with the PZT piezoelectric material (Patent Document 2). Specifically, Pb (M1 / 3N2 / 3) O3 (M = Mg, Zn, Co, Ni, Mn, N = Nb, Ta), Pb (M1 / 2N1 / 2) O3 (M = Sc, Fe, In, Yb, Ho, Lu, N = Nb, Ta), Pb (M1 / 2N1 / 2) O3 (M = Mg, Cd, Mn, Co, N = W, Re), Pb (M2 / 3N1 / 3) O3 (M = Mn, Fe, N = W, Re).

However, it is difficult to form the PZT-based oxide film described in Patent Document 1 described above to a thickness of 10 μm or less, for example. Further, since the green sheet is sintered at a temperature of 1000 ° C. or higher, there is a problem that the piezoelectric film shrinks to about 70% during heating. For this reason, since it is difficult to align the piezoelectric film and the structure such as the ink chamber with a dimensional accuracy of the order of several microns, a satisfactory small piezoelectric element has not been obtained.
In addition, as the thickness of the ceramic piezoelectric film formed by sintering the green sheet becomes thinner, the influence of crystal grain boundaries cannot be ignored, and good piezoelectric characteristics cannot be obtained. As a result, there is a problem that even if a piezoelectric film having a thickness of 10 μm or less is produced by sintering the green sheet, the piezoelectric film cannot obtain sufficient piezoelectric characteristics for discharging the recording liquid.
Further, a thin film of 10 μm or less can be obtained by sputtering, CVD, MBE, sol-gel method, or the like. However, since the piezoelectric film produced by these methods has a high density, there is a problem that the in-plane stress of the film becomes very high, and the adhesion with the lower electrode under the film becomes poor. As a piezoelectric element of an ink jet head, in order to withstand the stress generated by repeated driving, it is necessary to have high adhesion between the piezoelectric film and the lower electrode below it.

In addition, although the relaxor-based material described in Patent Document 2 described above has high piezoelectric characteristics, the piezoelectric characteristics are highly temperature-dependent and have a low Curie temperature. For this reason, when a relaxor-based material is used as a piezoelectric element, it is necessary to keep the operating environment temperature constant, and it has not been put into practical use as a piezoelectric element with little temperature dependence, not in accordance with the actual situation.
Japanese Patent Laid-Open No. 62-213399 JP 2004-179642 A

  An object of the present invention is to provide a piezoelectric body having high durability with high crystallinity controlled, excellent orientation, excellent adhesion with an electrode, suppressed film peeling, and high durability. It is in. It is another object of the present invention to provide a piezoelectric element, a liquid discharge head, and a liquid discharge apparatus using the same.

  It is another object of the present invention to obtain a piezoelectric body whose piezoelectric characteristics do not deteriorate even when the temperature of the operating environment changes, and to provide a piezoelectric element, a liquid ejection head, and a liquid ejection apparatus using the piezoelectric body.

  Furthermore, an object of the present invention is to obtain a method of manufacturing a piezoelectric body using a microfabrication technique generally used in a semiconductor process, and to have a discharge port formed at a high density using this method. An object of the present invention is to provide a liquid discharge head having a high level.

The present invention relates to a perovskite oxide described by the general formula ABO ₃ (the main component of the A site is Pb, and the main component of the B site is Mg, Zn, Sc, In, Yb, Ni, Nb, Ti and Ta Including at least three kinds of elements selected from the group consisting of a tetragonal crystal, a rhombohedral crystal, a pseudocubic crystal, an orthorhombic crystal, and a monoclinic crystal. A layered first crystal phase having a selected crystal phase and a crystal of the first crystal phase selected from tetragonal, rhombohedral, pseudocubic, orthorhombic or monoclinic A layered second crystal phase having a crystal phase different from the phase, and a boundary layer in which the crystal phase gradually changes in the thickness direction of the layer between the first crystal phase and the second crystal phase; And the laminated structure as a whole has a single crystal structure or a uniaxially oriented crystal structure. A piezoelectric element according to claim.

  The present invention also relates to a piezoelectric element having such a piezoelectric body, a liquid discharge head using the same, and a liquid discharge apparatus.

  The piezoelectric body of the present invention has excellent orientation and excellent piezoelectric properties with controlled crystallinity, high adhesion to the electrode, suppression of film peeling, and durability even with a thin film. High, it is possible to suppress deterioration of the piezoelectric characteristics even if the temperature of the operating environment changes. Further, it can be used for a piezoelectric element having a high degree of adhesion and a liquid discharge head to exhibit excellent piezoelectric characteristics.

In addition, the piezoelectric body of the present invention can obtain a highly reliable piezoelectric body by utilizing a microfabrication technique generally used in a semiconductor process. By using this, a high-density piezoelectric element or liquid discharge device can be obtained. A head and a liquid discharge apparatus can be manufactured.

The piezoelectric body of the present embodiment has a laminated structure including a single crystal structure or a uniaxial orientation (single orientation) crystal structure of a perovskite oxide described by a general formula ABO ₃ . The piezoelectric body has a layered structure including a plurality of different crystal phases, which is a layered crystal phase including a crystal phase selected from tetragonal, rhombohedral, pseudocubic, orthorhombic and monoclinic. The first crystal phase and the second crystal phase different from the first crystal phase in the stacked structure are not limited to the perovskite oxide ABO ₃ having different element compositions composed of the same elements, but the perovskite types having different element configurations and element compositions. Oxide ABO ₃ may be used. Further, not only those having two layers having different first crystal phase and second crystal phase in the laminated structure, but also third, fourth,... Crystal phases and three or more different crystal phases are interposed therebetween. It may be combined with a boundary layer. Further, the present invention is characterized in that a crystal phase (boundary layer) in which the crystal phase gradually changes in the layer thickness direction is provided between the different crystal phases. These first crystal phase, boundary layer, and second crystal phase may be periodically laminated. Each crystal phase is, for example, epitaxially grown and constitutes a multilayer structure, and exhibits a single crystal structure or a uniaxially oriented crystal structure as the entire multilayer structure.

In order for the multilayer structure having a plurality of different crystal phases to exhibit a single crystal or a uniaxially oriented crystal structure as a whole, the crystal phase of the perovskite oxide ABO ₃ constituting each layer of the multilayer structure must be <100> oriented. Is preferred. When the tetragonal, rhombohedral, pseudocubic, orthorhombic, and monoclinic crystals constituting each layer of the laminated structure are oriented to <100>, the entire laminated structure can have a single crystal or uniaxially oriented structure. Conceivable. In the perovskite oxide of this embodiment, the tetragonal system, rhombohedral system, pseudocubic system, orthorhombic system, and monoclinic system have lattice constants close to each other, and these crystal phases have crystal axes. It exists in a state in which the direction is oriented in the film thickness direction, and has a single crystal structure or a uniaxially oriented crystal structure.

  As a piezoelectric body having such a laminated structure, for example, as shown in FIG. 1, a first crystal phase 21 and a second crystal phase 22 having a certain crystal structure, and a boundary layer 211 provided therebetween. 221 may be mentioned. Specifically, as the boundary layer, the following is provided between the tetragonal first crystal phase 21 having a single crystal structure and the rhombohedral second crystal phase 22 having a single crystal structure. It has such a crystal structure. The boundary layer 211 has a crystal phase that gradually changes from tetragonal to rhombohedral toward the crystal phase 22 from the crystal phase 21 side. The boundary layer 221 has a crystal phase that gradually changes from rhombohedral to tetragonal toward the crystal phase 21 from the crystal phase 22 side.

  Here, the gradual change of the crystal phase of the boundary layer includes a case where the crystal phases of the crystal phase 21 and the crystal phase 22 are mixed. The mixed phase is formed by combining two or more crystal phases into a single crystal or a uniaxial crystal structure. Unlike the case where multiple crystal phases are included in a polycrystalline state with different crystal axis directions and there are grain boundaries, there are multiple crystal phases in a single perovskite oxide particle. Thus, it is preferable to form a crystal integrally.

  With such a configuration, strain from a biased direction can be evenly dispersed and absorbed, and therefore peeling due to strain can be suppressed even with a micron-order film thickness at which peeling is likely to occur. In other words, a piezoelectric body having high adhesion between the piezoelectric film and the electrode, suppressing film peeling and having high durability can be obtained, and stress applied to each layer of the crystal phase can be further relaxed, thereby improving the durability of the piezoelectric body. Further improvement can be achieved.

  In addition, when a defect such as a fine crack is generated in a specific phase, there is a possibility that the crack may spread in a piezoelectric body having a single crystal phase structure. However, since the Young's modulus for each layer differs depending on the laminated structure, the cracks generated from the layer having a large Young's modulus are prevented from progressing to the layer having the next large Young's modulus beyond the layer having the small Young's modulus. For this reason, it is difficult for cracks to spread, and a piezoelectric body having high durability as a whole can be obtained.

  Further, in such a laminated structure, when it is formed by epitaxial growth, a crystal phase having a different composition disperses and absorbs stress applied to the film itself in the phase change accompanying cooling from the film forming temperature to room temperature in the film forming process. To do. Furthermore, a specific crystal phase absorbs strain for each specific temperature region, and as a whole, it has good piezoelectric characteristics in a wide temperature region. In addition, by combining a relaxor material having a low Curie temperature and a relaxor material having a high Curie temperature, a piezoelectric body having sufficient piezoelectric properties can be obtained without impairing the piezoelectric properties even when the environmental temperature fluctuates. .

The crystal phase constituting such a laminated structure is a crystal phase made of perovskite oxide ABO ₃ . In the perovskite oxide ABO ₃ , the main component of the A site contains Pb, and the main component of the B site contains at least three elements selected from Mg, Zn, Sc, In, Yb, Ni, Nb, Ti, and Ta. . When the B site contains at least three elements, a crystal phase boundary can be suitably formed.

Specific examples of the perovskite oxide ABO ₃ in this embodiment include the following seven perovskite oxides.

Examples of the perovskite oxide (I) include (Pb _km α _lm ) _xm (Mg _mm Nb _{nm Tiom} β _pm ) _ym O ₃ type.

In the formula, 1 ≦ xm / ym <1.5, km + lm = 1, 0.7 ≦ km ≦ 1, 0 ≦ lm ≦ 0.3, mm + nm + om + pm = 1, 0.1 <mm <0.3, 0.3 <Nm <0.5, 0.2 <om <0.4, and 0 ≦ pm <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Sc, In, Yb, Ni, Ta, Co, W, Fe, Sn, or Zn. The elements of The perovskite oxide (I) has a pseudo cubic crystal and a tetragonal crystal.

Examples of the perovskite oxide (II) include (Pb _kz α _lz ) _xz (Zn _{mz Nbnz} Ti _oz β _pz ) _yz O ₃ type.

  In the formula, 1 ≦ xz / yz <1.5, kz + lz = 1, 0.7 ≦ kz ≦ 1, 0 ≦ lz ≦ 0.3, mz + nz + oz + pz = 1, 0.2 <mz <0.4, 0.5 <Nz <0.7, 0.05 <oz <0.20, and 0 ≦ pz <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Sc, In, Yb, Mg, Ta, Co, W, Fe, Sn, or Ni. The elements of Perovskite oxide (II) takes pseudo cubic and tetragonal crystals.

Examples of the perovskite oxide (III) include (Pb _kn α _ln ) _xn (Ni _mn Nb _nn Ti _on β _pn ) _yn O ₃ type.

  In the formula, 1 ≦ xn / yn <1.5, kn + ln = 1, 0.7 ≦ kn ≦ 1, 0 ≦ ln ≦ 0.3, mn + nn + on + pn = 1, 0.1 <mn <0.3, 0.3 <Nn <0.5, 0.3 <on <0.5, 0 ≦ pn <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Sc, In, Yb, Mg, Ta, Co, W, Fe, Sn, or Zn. The elements of The perovskite oxide (III) has a pseudo cubic crystal and a tetragonal crystal.

Examples of the perovskite oxide (IV) include (Pb _kt α _lt ) _xt (Sc _mt Ta _nt Ti _ot β _pt ) _yt O ₃ type.

  In the formula, 1 ≦ xt / yt <1.5, kt + lt = 1, 0.7 ≦ kt ≦ 1, 0 ≦ lt ≦ 0.3, mt + nt + ot + pt = 1, 0.1 <mt <0.4, 0.1 <Nt <0.4, 0.3 <ot <0.5, 0 ≦ pt <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Nb, In, Yb, Mg, Ni, Co, W, Fe, Sn, or Zn. The elements of The perovskite oxide (IV) has a pseudo cubic crystal and a tetragonal crystal.

It can be mentioned perovskite oxide as _{(V) (Pb ks α ls} ) xs (Sc ms Nb ns Ti os β ps) ys O 3 type.

  In the formula, 1 ≦ xs / ys <1.5, ks + ls = 1, 0.7 ≦ ks ≦ 1, 0 ≦ ls ≦ 0.3, ms + ns + os + ps = 1, 0.1 <ms <0.4, 0.1 <Ns <0.4, 0.3 <os <0.5, 0 ≦ ps <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Ta, In, Yb, Mg, Ni, Co, W, Fe, Sn, or Zn. The elements of The perovskite oxide (V) is rhombohedral and tetragonal.

It can be mentioned perovskite oxide as _{(VI) (Pb ky α ly} ) xy (Yb my Nb ny Ti oy β py) yy O 3 type.

  In the formula, 1 ≦ xy / yy <1.5, ky + ly = 1, 0.7 ≦ ky ≦ 1, 0 ≦ ly ≦ 0.3, my + ny + oy + py = 1, 0.1 <my <0.4, 0.1 <Ny <0.4, 0.4 <oy <0.6, and 0 ≦ py <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Sc, In, Ta, Mg, Ni, Co, W, Fe, Sn, or Zn. The elements of Perovskite oxide (VI) is monoclinic or tetragonal.

It can be mentioned perovskite oxide as _{(VII) (Pb ki α li} ) xi (In mi Nb ni Ti oi β pi) yi O 3 type.

  In the formula, 1 ≦ xi / yi <1.5, ki + li = 1, 0.7 ≦ ki ≦ 1, 0 ≦ li ≦ 0.3, mi + ni + oi + pi = 1, 0.2 <mi <0.4, 0.2 <Ni <0.4, 0.2 <oi <0.5, and 0 ≦ pi <0.3 are all satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any of Pb, Sc, In, Yb, Mg, Ni, Co, W, Fe, Sn, or Zn. The elements of Perovskite oxide (VII) has pseudo cubic and tetragonal crystals.

The perovskite oxides (I) to (VII) are morphotropic phase boundaries (commonly called
MPB), it is considered that it can have a plurality of crystal phases in a single crystal structure or a uniaxially oriented crystal structure. As a result, a boundary layer can be formed, the film uniformity is good, the piezoelectric characteristics are high, and the dielectric constant is high.

Further, as the laminated structure of the piezoelectric body of the present embodiment, it is preferable that at least two of the crystal phase layers have different thicknesses. For example, as shown in FIG. 2, the piezoelectric body has a crystal phase 31 with a film thickness T ₁ , a crystal phase 32 with a film thickness T ₂ , and a crystal phase 33 with a film thickness T ₃ , and the film thicknesses T ₁ , T ₂ , T ₃ may have different thicknesses. Between each crystal phase, there are boundary layers 311, 321 and 331 in which the crystal phase gradually changes. The film thicknesses T ₁ , T ₂ , and T ₃ here indicate the distances from the center of the boundary layer to the center of the next boundary layer. As the piezoelectric body having such a laminated structure, it is preferable that the film thickness of the crystal phase layer most suitable for the conditions for using the piezoelectric body is sufficiently thick. It can be relaxed in the crystalline phase layer. In the piezoelectric body having a different thickness depending on each crystal phase, the ratio of the thickness of each crystal phase can be distributed according to the use conditions, and the piezoelectric body can be made according to the use environment. The boundary layer preferably changes gradually, but may be a mixed phase of crystal phases in contact with the boundary layer.

The film thickness of each layer forming the laminated structure in the piezoelectric body of the present embodiment is preferably 1 nm or more and 1000 nm or less. If the thickness of each layer is 1 nm or more, sufficient piezoelectric characteristics can be obtained in the piezoelectric body, and if it is 1000 nm or less, peeling due to in-plane stress in the laminated structure can be suppressed.
[Piezoelectric element]
The piezoelectric element of the present embodiment is not particularly limited as long as it has the piezoelectric body of the present embodiment and a pair of electrodes provided in contact with the piezoelectric body. As an example of the piezoelectric element of this embodiment, as shown in FIG. 3, a piezoelectric element having a laminated structure in which a base body 41, a diaphragm 42, a buffer layer 43, a lower electrode 44, a piezoelectric body 45, and an upper electrode 46 are sequentially laminated. The body element 51 can be mentioned.

As a material of the substrate in the piezoelectric element of the present embodiment, a material having good crystallinity is preferable. For example, Si or the like is preferable, and specifically, SOI or the like in which a SiO ₂ film is formed on Si can be given. Examples of the thickness of the substrate include 100 to 1000 μm.

The diaphragm is preferably provided to transmit the displacement of the piezoelectric body, has high lattice matching with the substrate, and has a sufficiently high Young's modulus to function as a diaphragm. When the material of the substrate is silicon oxide, the material of the diaphragm is preferably, for example, stabilized zirconia. When SOI is used as the substrate, an SiO ₂ layer on the Si single crystal layer may be used as the diaphragm. Examples of the thickness of the vibrating body include 2 to 10 μm.

The buffer layer is provided to play a role of matching the lattice matching between the crystal lattice constant of the substrate and the crystal lattice constant of the piezoelectric body, and may be omitted if the lattice matching between the substrate and the piezoelectric body is good. it can. The buffer layer may have several layers to achieve its function. The material of the buffer layer is preferably a material having high crystal lattice matching even with respect to the diaphragm directly below. When the material of the substrate is silicon, for example, stabilized zirconia YSZ (Y ₂ O ₃ —ZrO _2). ), CeO _{2 and the} like.

The lower electrode may be provided immediately above the buffer layer 43 or may be provided between the diaphragm 42 and the buffer layer 43. Further, when the buffer layer is not provided, the lower electrode may have the function of the buffer layer. In this case, the lower electrode is provided via the adhesion layer in order to improve the adhesion with the diaphragm. May be. As the material of the lower electrode, platinum group metals and these oxide-based conductive materials are preferable. Specific examples of the material for the lower electrode include platinum group metals such as Ru, Rh, Pd, Os, Ir, and Pt, and oxide-based conductive materials such as SrRuO ₃ , BaPbO ₃ , and RuO ₃ . Examples of the material for the adhesion layer include metals such as Ti, Cr, and Ir, and examples of these oxides include TiO ₂ and IrO ₂ .

  Since such a lower electrode 44 affects the orientation crystal orientation of the piezoelectric body provided thereon, the preferential orientation crystal orientation of the substrate surface is any one of (010), (101), (110), and (111). It is preferable that When the preferentially oriented crystal orientation of the substrate surface of the lower electrode is (010), (101), (110), (111), the piezoelectric body 45 to be laminated has the preferentially oriented crystal orientation of (100), (001), respectively. , (010), (101), (110), (111). Further, since the piezoelectric characteristics of the piezoelectric body 45 are particularly good when the preferential orientation crystal orientation is (001) or (111), the preferential orientation crystal orientation of the substrate surface of the lower electrode is (001) or (111). It is preferable.

  In such a metal thin film or oxide conductive material thin film constituting the lower electrode, the crystal orientation rate is preferably 70% or more. The crystal orientation ratio is a ratio in the peak intensity of the film measured by XRD (X-ray diffraction) θ-2θ measurement. When the crystal orientation ratio of the metal electrode thin film is 70% or more, the lower electrode has good electrical characteristics, and the piezoelectric body 45 provided thereon has excellent crystallinity. It is more preferable that the crystal orientation rate of the metal thin film or the oxide conductive material thin film of the lower electrode is 85% or more. Further, the film thickness of the lower electrode is preferably 100 nm to 1000 nm, and the film thickness of the adhesion layer is preferably 5 nm to 300 nm, more preferably 10 to 70 nm.

  The piezoelectric body used for the piezoelectric element of the present embodiment is the piezoelectric body of the present embodiment. The film thickness of the piezoelectric body is preferably 100 nm or more and 10 μm or less, more preferably 500 nm or more and 8 μm or less. If the thickness of the piezoelectric body is 100 nm or more, the piezoelectric element is durable against stress generated by repeated driving when the piezoelectric element is used for a liquid discharge head, and if it is 10 μm or less, the occurrence of film peeling is suppressed. can do.

  The upper electrode 46 is provided immediately above the piezoelectric body 45 and charges the piezoelectric body together with the lower electrode. An adhesion layer made of the same material as the adhesion layer provided between the lower electrode and the diaphragm may be provided between the upper electrode and the piezoelectric body. The material of the upper electrode 46 can be the same as that of the lower electrode.

Specific examples of the piezoelectric element according to this embodiment include the following layer configurations. This layer structure is displayed as an upper electrode 46 // piezoelectric body 45 // lower electrode 44 // vibrating plate 42, and indicates a different laminated structure.
Example 1:
Pt / Ti // PbMgNbO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ / PbMgNbO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ // Pt / Ti // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 2:
Pt / Ti // PbMgNbO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ / PbMgNbO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ // SrRuO ₃ / Pt // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 3:
Pt / Ti // PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ / PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ // Pt / Ti // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 4:
Pt / Ti // PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ / PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ // SrRuO ₃ / Pt // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 5:
Pt / Ti // PbYbNbO ₃ -PbTiO ₃ / PbInNbO ₃ -PbTiO ₃ / PbYbNbO ₃ -PbTiO ₃ / PbInNbO ₃ -PbTiO ₃ // Pt / Ti // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 6:
Pt / Ti // PbYbNbO ₃ -PbTiO ₃ / PbInNbO ₃ -PbTiO ₃ / PbYbNbO ₃ -PbTiO ₃ / PbInNbO ₃ -PbTiO ₃ // SrRuO ₃ / Pt // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 9:
Pt / Ti // PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ / PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ / PbNiNbO ₃ -PbTiO ₃ // Pt / Ti // YSZ ( ₂ O ₃ -ZrO ₂ ) / Si
Example _{10: Pt / Ti // PbZnNbO 3} -PbTiO 3 / PbScTaO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 / PbZnNbO 3 -PbTiO 3 / PbScTaO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 // SrRuO 3 / Pt / / YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 11:
_{Pt / Ti // PbMgNbO 3 -PbTiO 3} / PbNiNbO 3 -PbTiO 3 / PbYbNbO 3 -PbTiO 3 / PbInNbO 3 -PbTiO 3 / PbMgNbO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 / PbYbNbO 3 -PbTiO 3 / PbInNbO 3 - PbTiO ₃ // Pt / Ti // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 12:
_{Pt / Ti // PbMgNbO 3 -PbTiO 3} / PbNiNbO 3 -PbTiO 3 / PbYbNbO 3 -PbTiO 3 / PbInNbO 3 -PbTiO 3 / PbMgNbO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 / PbYbNbO 3 -PbTiO 3 / PbInNbO 3 - PbTiO ₃ // SrRuO ₃ / Pt // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 13:
_{Pt / Ti // PbMgNbO 3 -PbTiO 3} / PbNiNbO 3 -PbTiO 3 / PbMgNbO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 / PbMgNbO 3 -PbTiO 3 / PbNiNbO 3 -PbTiO 3 / PbMgNbO 3 -PbTiO 3 / PbNiNbO 3 - PbTiO ₃ // Pt / Ti // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
Example 14
_{Pt / Ti // PbZnNbO 3 -PbTiO 3} / PbScTaO 3 -PbTiO 3 / PbZnNbO 3 -PbTiO 3 / PbScTaO 3 -PbTiO 3 / PbZnNbO 3 -PbTiO 3 / PbScTaO 3 -PbTiO 3 / PbZnNbO 3 -PbTiO 3 / PbScTaO 3 - PbTiO ₃ / PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ / PbZnNbO ₃ -PbTiO ₃ / PbScTaO ₃ -PbTiO ₃ // SrRuO ₃ / Pt // YSZ (Y ₂ O ₃ -ZrO ₂ ) / Si
[Liquid discharge head]
The liquid ejection head according to the present embodiment includes an ejection port, an individual liquid chamber communicating with the ejection port, the piezoelectric element according to the present embodiment provided corresponding to the individual liquid chamber, the individual liquid chamber, and the piezoelectric element. If it has a diaphragm provided between, it will not be restrict | limited in particular. As an example of the liquid discharge head of the present embodiment, an ink jet head shown in FIG. 3 can be cited. Such an ink jet head is provided with a base 41 and a pressure chamber 61 which is a plurality of individual liquid chambers provided in parallel with the base. Each pressure chamber is provided with a liquid discharge port (discharge port) 53 and a piezoelectric element 51, and a diaphragm 42 is provided between the pressure chamber and the piezoelectric element. In this ink jet head, the discharge ports 53 are formed at a predetermined interval in the nozzle plate 52 provided on the lower side of the base body 41, but can also be provided on the side surface side.

  As an example, the piezoelectric element 51 is provided corresponding to each pressure chamber 61. Each piezoelectric element 51 includes, for example, a laminated body in which a buffer layer 43, a lower electrode 44, a piezoelectric body 45 that is a piezoelectric thin film, and an upper electrode 46 are sequentially laminated.

  In the liquid discharge head of this embodiment, the liquid in the individual liquid chamber is discharged from the discharge port by the volume change in the individual liquid chamber caused by the vibration plate to which the displacement of the piezoelectric body is transmitted.

  The liquid discharge head of this embodiment can be applied to a liquid discharge unit of an apparatus that discharges various liquids in addition to an inkjet head.

In the liquid discharge head according to the present embodiment, a piezoelectric element having a crystal orientation in which the vibration plate, the buffer layer constituting the piezoelectric element, the lower electrode, the piezoelectric body, the upper electrode, etc. are aligned on the substrate is used. There is little variation in the performance of each piezoelectric element. For this reason, a device with high adhesion can be obtained, and piezoelectric characteristics and mechanical characteristics sufficient for miniaturization can be obtained. In addition, by using a highly oriented crystal piezoelectric body, the durability of the piezoelectric element is improved, and the liquid discharge head is excellent in durability.
[Liquid ejection device]
The liquid ejection apparatus according to the present embodiment includes the liquid ejection head according to the present embodiment.

  An example of the liquid ejecting apparatus according to the present embodiment is an ink jet recording apparatus. As shown in FIG. 4, the ink jet recording apparatus includes an automatic feeding unit 97 that automatically feeds recording paper as a recording medium into the apparatus main body 96. Furthermore, a transport unit 99 that guides the recording paper fed from the automatic feeding unit 97 to a predetermined recording position and guides the recording paper from the recording position to the discharge port 98, a recording unit 91 that performs recording on the recording paper transported to the recording position, And a recovery unit 90 that performs recovery processing on the recording unit 91. The recording unit 91 includes a carriage 92 that houses the liquid ejection head of this embodiment and is reciprocated on the rail.

  In such an ink jet recording apparatus, the carriage 92 is moved on the rail by an electrical signal sent from a computer, and the piezoelectric body is displaced when a driving voltage is applied to the electrodes sandwiching the piezoelectric body. Printing is performed by pressurizing each piezoelectric chamber through the vibration plate by the displacement of the piezoelectric body and discharging ink from the discharge port.

  In the liquid ejection apparatus of this embodiment, it is possible to eject liquid droplets uniformly at a high speed, and the apparatus can be miniaturized.

Although the above example has been illustrated as a printer, the liquid ejection apparatus according to the present embodiment can be used as an industrial liquid ejection apparatus in addition to an inkjet recording apparatus such as a facsimile, a multifunction peripheral, and a copying machine.
[Piezoelectric manufacturing method]
In the manufacture of the piezoelectric body of the present embodiment, a layer having a crystal phase of any one of tetragonal, rhombohedral, pseudocubic, orthorhombic and monoclinic is formed by sputtering, and a plurality of layers having different crystal phases. It can be based on the method of laminating. This can be achieved by having a step of providing a target in which a plurality of piezoelectric materials are arranged in different regions, and a step of performing sputtering while changing the region of the target to be sputtered.

For example, as a method of manufacturing the piezoelectric body shown in FIG. 1, a piezoelectric body having an elemental composition of a base material to be a piezoelectric base body and a piezoelectric material constituting a crystal phase, for example, the above-mentioned perovskite oxide ABO ₃ of a sintered product. A chamber provided with a target on which a material is disposed is used. After the chamber is evacuated to high vacuum, a glow discharge is generated by applying a gap between the substrate and the target to ionize the introduced argon gas or the like. Further, the ions are accelerated by a high electric field to strike the target, and a crystal phase is grown on the substrate by a recoil element from the target. In particular, in order to manufacture a piezoelectric body by periodically laminating different crystal phases, as shown in FIG. 5, two types of crystal phases are formed in different regions obtained by dividing the target region as shown in FIG. A piezoelectric material, composition 1, and composition 2 are used. The opening of the shutter is made to face the area of the target piezoelectric material of the target. Only the region of the corresponding piezoelectric material is sputtered through the opening for a predetermined time to form a recoil element on the substrate. Thereafter, the shutter is gradually moved so that the opening faces the piezoelectric material region having another composition forming the next crystal phase, and sputtering is performed. By repeating this, it is possible to obtain a piezoelectric body having a laminated structure in which different compositions, that is, two different crystal phases and a boundary layer therebetween are sequentially laminated. Further, in the case of a piezoelectric body having a laminated structure in which three kinds of crystal phases and a boundary layer are laminated, as shown in FIG. 6, three kinds of piezoelectric materials constituting different crystal phases, compositions 1 to 3, The target area is arranged in different areas of the three divided areas. A piezoelectric body having a laminated structure in which a crystal phase of composition 1 to 3 and a boundary layer thereof are laminated by performing sputtering while sequentially opening the shutter opening to the corresponding piezoelectric material region in order. Can be obtained.

The perovskite oxide ABO ₃ used as a target can be obtained, for example, by a sintering method or a powder method prepared with a desired composition.

  In addition, the manufacture of the boundary layer in which the crystal structure gradually changes in the layer thickness direction is performed by adjusting the moving speed of the shutter that opposes the opening to the region where the different piezoelectric materials are arranged. A crystal phase in which the crystal phase gradually changes is produced by setting the shutter movement speed to an opening movement speed that allows film formation corresponding to a crystal phase that gradually changes in the thickness direction of the piezoelectric body. be able to.

As described above, by epitaxial growth using the elemental composition of the perovskite oxide ABO ₃ as a target, the piezoelectric body as a whole has a single crystal structure or a uniaxially oriented structure while having a laminated structure having a plurality of crystal phases. A piezoelectric body having the same can be obtained.

[Method for Manufacturing Piezoelectric Element]
Examples of the method for manufacturing the piezoelectric element of the present embodiment include a method using a thin film deposition technique. In manufacturing the piezoelectric element having the above-described configuration, a method for manufacturing the diaphragm 42 may be a thin film manufacturing method such as sputtering, CVD, laser ablation, or MBE. In particular, in the sputtering method, an oxide thin film epitaxially grown on the base body 41 can be obtained by sufficiently heating the deposition substrate during heating.

  In addition, as a method for manufacturing the lower electrode 44 and the upper electrode stacked on the substrate 41 in the manufacture of the piezoelectric element, a thin film manufacturing technique such as sputtering, CVD, laser ablation, or MBE may be used. it can. By these methods, a film can be formed by orienting the electrode material in a specific direction. Here, in using the film forming method, substrate heating during film formation is important, and for example, a temperature range of 500 to 700 ° C. can be used.

  For the production of the buffer layer of the piezoelectric element, a method similar to the method for producing an electrode using a buffer material can be used.

[Liquid discharge head manufacturing method]
As a manufacturing method of the liquid discharge head of this embodiment, a method using a thin film deposition technique can be exemplified. In order to manufacture the liquid discharge head according to the present embodiment, a method of providing the individual liquid chamber (pressure chamber) 61 in the base body 41 of the piezoelectric element having the above-described structure, and a method of providing the individual liquid chamber in another base body and the piezoelectric body. It can be based on a method of joining the element.

  As the former method, a piezoelectric element is manufactured by the same method as described above, and a part of the base body 41 is removed at a constant pitch to form a plurality of concave portions to be individual liquid chambers. For example, wet etching using anisotropic etching, dry etching, sand mill, or the like can be used to form the recess. The liquid discharge head can be manufactured by joining the nozzle plate 52 having the discharge port 53 perforated corresponding to the concave portion, or joining the discharge plate 53 and the nozzle plate having the communication hole. The material of the nozzle plate may be the same as or different from the substrate to be bonded, such as SUS, Ni, etc., and the difference in thermal expansion coefficient from the substrate to be bonded is 1E-6 / ° C. to 1E−. A material that is 8 / ° C is preferred. Examples of a method for perforating the discharge port in the nozzle plate include methods such as etching, machining, and laser beam irradiation.

  As a method for bonding the base body 41 and the nozzle plate 52, a method using an organic adhesive may be used, but a method using metal bonding with an inorganic material is preferable. Examples of materials used for metal bonding include In, Au, Cu, Ni, Pb, Ti, and Cr. These metal materials can bond the base and the nozzle plate at a low temperature of 250 ° C. or less, and the difference in thermal expansion coefficient with the base is small. In addition, damage to the piezoelectric body can be suppressed, which is preferable.

Hereinafter, the liquid discharge head using the piezoelectric body and the piezoelectric element of the present embodiment will be specifically described. The technical scope of the piezoelectric body, the piezoelectric element of the present embodiment, and the liquid discharge head using the piezoelectric body element is not limited to this.
[Example 1]
A liquid discharge head was produced by the following method.

First, using a sputtering apparatus (L-210-FH (manufactured by ANELVA)), a stabilized zirconia YSZ (Y ₂ O ₃ —ZrO ₂ ) film was formed on the opening of the Si substrate to produce a diaphragm. At this time, the Si substrate is heated to 800 ° C., Ar and O ₂ are used as ions to be ionized, the applied power between the Si substrate and the target is 60 W, the pressure in the apparatus is 1.0 Pa, and the crystal is grown to be uniaxially oriented. A diaphragm having a thickness of 200 nm was obtained.

  Next, a lower electrode was produced by the same method as the method for producing the diaphragm. At this time, Pt is used as the target, the substrate temperature is 600 ° C., the ionizing gas Ar is used, the applied power between the diaphragm and the target is 100 W, and the pressure in the apparatus is 0.5 Pa. A 400 nm Pt film was obtained.

Then, using the said sputtering apparatus, what was shown in FIG. 5 which has arrange | positioned 2 types of perovskite oxides of the following target composition (1) (2) as a target in a different area | region was used. After the shutter opening was made to face one composition region of the target, fixed for a certain period of time and deposited on the substrate, the shutter was moved so that the opening faced the other composition region, and deposition was repeated. A piezoelectric body was obtained in which 20 crystal phases having different compositions were alternately laminated, and a boundary layer was laminated between the crystal phases. The substrate temperature was 650 ° C., ionizing gases Ar and O ₂ were used, the applied power between the electrode and the target was 100 W, and the pressure in the apparatus was 0.3 Pa. The sputtering time of the target composition (1) and (2) regions was 8 min, and the movement time (boundary layer formation time) from one region of the target of the shutter opening to the next region was 2 min. A piezoelectric body having a film thickness of 3000 nm composed of a boundary layer of tetragonal crystals, pseudo cubic crystals and mixed phases thereof as shown in FIG. 1 was obtained.

Target composition
(1) (Pb _km α _lm ) _xm (Mg _mm Nb _nm Ti _om β _pm ) In _ym O ₃ , 1 ≦ xm / ym <1.2, km + lm = 1, km = 1, lm = 0, mm + nm + om + pm = 1 , Mm = 0.22, nm = 0.44, om = 0.33, pm = 0
(2) In (Pb _kz α _lz ) _xz (Zn _mz Nb _nz Ti _oz β _pz ) _yz O ₃ , 1 ≦ xz / yz <1.2, kz + lz = 1, kz = 1, lz = 0, mz + nz + oz + pz = 1 , Mz = 0.30, nz = 0.61, oz = 0.09, pz = 0
Then, the upper electrode was produced by the same method as the production method of the lower electrode.

Next, the Si substrate was subjected to ICP dry etching from the surface opposite to the surface on which the vibration plate 42 was provided to remove the central portion to form a recess. At this time, the temperature of the substrate was 20 ° C., the gases used were SF ₆ and C ₄ F ₈ , the dielectric of the high frequency coil was 1800 W in RF, and the pressure in the apparatus was 4.0 Pa. A Si nozzle plate provided with a liquid outlet 53 was bonded to a Si substrate having a recess by a Si-Si bonding method. A liquid discharge head having a length of 5000 μm and a width of 100 μm of the diaphragm of the piezoelectric element was produced.

With respect to the obtained piezoelectric element and liquid discharge head, the amount of displacement of the piezoelectric element at an applied voltage of 20 V and 10 kHz, the discharge amount of liquid droplets and the discharge speed of the liquid discharge head were measured. The results are shown in Tables 1 and 2.
[Example 2]
A liquid ejection head was produced by the same method as in Example 1 except that the target composition for producing the piezoelectric body was as follows, and the target shown in FIG. Target compositions (1) to (3) were respectively disposed as piezoelectric materials in the three target regions. The sputtering time for each composition region was 15 min, 13 min, and 11 min, respectively, and the moving time of the shutter opening was 2 min. A piezoelectric body having a film thickness of 3000 nm composed of a tetragonal crystal layer, a pseudo-cubic crystal layer, and a monoclinic crystal phase with a film thickness of 50 nm and 20 layers each and a mixed phase boundary layer thereof was obtained. By changing the film formation time of each crystal phase, it was possible to form piezoelectric bodies having different film thicknesses of each crystal phase as shown in FIG.

Target composition
(1) (Pb _km α _lm ) _xm (Mg _mm Nb _nm Ti _om β _pm ) In _ym O ₃ , 1 ≦ xm / ym <1.2, km + lm = 1, km = 1, lm = 0, mm + nm + om + pm = 1 , Mm = 0.22, nm = 0.44, om = 0.33, pm = 0
(2) In (Pb _kz α _lz ) _xz (Zn _mz Nb _nz Ti _oz β _pz ) _yz O ₃ , 1 ≦ xz / yz <1.2, kz + lz = 1, kz = 1, lz = 0, mz + nz + oz + pz = 1 , Mz = 0.30, nz = 0.61, oz = 0.09, pz = 0
(3) (Pb _ky α _ly ) _xy (Yb _my Nb _ny T _oy β _py ) _yy O ₃ 1 ≦ xy / yy <1.2, ky + ly = 1, ky = 1, ly = 0, my + ny + oy + py = 1 , My = 0.25, ny = 0.25, oy = 0.50, py = 0
For the obtained piezoelectric element and liquid discharge head, the displacement amount, the droplet discharge amount, and the discharge speed were measured in the same manner as in Example 1. The results are shown in Tables 1 and 2.
[Example 3]
The following (1) to (4) are used as the target composition for producing the piezoelectric body, and the liquid discharge head is manufactured in the same manner as in the first and second embodiments except that a target in which the piezoelectric material is arranged in each of the four target areas is used. Was made. The sputtering time of each composition region was 20 min, 18 min, 16 min, and 14 min, respectively, and the moving time of the shutter opening was 4 min. A piezoelectric body having a film thickness of 3000 nm composed of 15 layers each of tetragonal crystal, pseudo cubic crystal, tetragonal crystal and rhombohedral crystal and a boundary layer was obtained. The target divided region and the sputtering time were appropriately changed to form a piezoelectric body in which a plurality of crystal phases having a target film thickness were laminated.

Target composition
(1) (Pb _kn α _ln ) _xn (Ni _mn Nb _nn Ti _on β _pn ) _yn O ₃
(In the formula, 1 ≦ xn / yn <1.5, kn + ln = 1, kn = 0.9, ln = 0.1, mn + nn + on + pn = 1, mn = 0.2, nn = 0.4, on = 0. 35, pn = 0.05 is satisfied, α is La, and β is In.
(2) (Pb _kt α _lt ) _xt (Sc _mt Ta _nt Ti _ot β _pt ) _yt O ₃
(In the formula, 1 ≦ xt / yt <1.5, kt + lt = 1, kt = 0.9, lt = 0.1, mt + nt + ot + pt = 1, mt = 0.28, nt = 0.28, ot = 0. 40, pt = 0.04 is satisfied, α is La, and β is Nb.
(3) (Pb _ki α _li ) _xi (In _mi Nb _ni Ti _oi β _pi ) _yi O ₃
(Wherein 1 ≦ xi / yi <1.5, ki + li = 1, ki = 0.9, li = 0.1, mi + ni + oi + pi = 1, mi = 0.23, ni = 0.23, oi = 0. 50, pi = 0.04, α is La, and β is Mg.
_{(4) (Pb ks α ls} ) xs (Sc ms Nb ns Ti os β ps) ys O 3
(Where 1 ≦ xs / ys <1.5, ks + ls = 1, ks = 0.9, ls = 0.1, ms + ns + os + ps = 1, ms = 0.25, ns = 0.25, os = 0. 43, ps = 0.07 is satisfied, α is La, and β is In.

  With respect to the obtained piezoelectric element and liquid discharge head, the displacement amount, the droplet discharge amount, and the discharge speed were measured in the same manner as in Examples 1 and 2. The results are shown in Tables 1 and 2.

[Comparative Example 1]
The target composition for producing the piezoelectric body is (Pb _1-x M _x ) (Z _ry Ti _1-y ) O ₃ formula, where x = 0, y = 0.50 sintered body, and the heating temperature of the substrate is 600 ° C. Except for this, a liquid discharge head was manufactured in the same manner as in Example 1. A single layer structure was obtained from tetragonal crystals.

  For the obtained piezoelectric element and liquid discharge head, the displacement amount, the droplet discharge amount, and the discharge speed were measured in the same manner as in Example 1.

  From the results, the displacement amount of the piezoelectric element (Example 1) formed by stacking two kinds of crystal phases of tetragonal crystal and pseudo cubic crystal was 0.65 nm. Further, the displacement amount of the piezoelectric element (Example 2) composed of three kinds of crystal phases of a tetragonal crystal layer, a pseudo cubic crystal layer, and a monoclinic crystal layer was 0.70 nm. Further, the displacement amount of the piezoelectric element (Example 3) formed by stacking crystal phases of a combination of tetragonal, pseudocubic, tetragonal and rhombohedral layers was 0.80 nm. On the other hand, the displacement amount of the piezoelectric element consisting only of the tetragonal layer of Comparative Example 1 was 0.30 nm.

  From the results, the discharge amount when the voltage of 20 V was applied (10 kHz) to the liquid discharge head of Example 1 was 20 pl, and the discharge speed was 15 m / sec. When a voltage of 20 V was applied to the liquid discharge head of Example 2 (10 kHz), the discharge amount was 22 pl and the discharge speed was 16 m / sec. When a voltage of 20 V was applied (10 kHz) to the liquid discharge head of Example 3, the discharge amount was 25 pl and the discharge speed was 18 m / sec. On the other hand, the discharge amount and discharge speed of the liquid discharge head of Comparative Example 1 were 12 pl and 11 m / sec, respectively, and the discharge amount and discharge speed were lower than in the example.

Further, when endurance tests of these liquid discharge heads were performed, the liquid discharge heads of the examples of the present embodiment had no discharge failure nozzles even after exceeding 10 ⁹ times, whereas in the comparative examples, 10 ⁶ to 10 Separation occurred after ⁷ times, and a non-ejection nozzle part was generated.

It is a schematic diagram which shows the laminated structure of one embodiment of the piezoelectric material of this invention. It is a schematic diagram which shows the laminated structure of one embodiment of the piezoelectric material of this invention. It is a perspective view showing one embodiment of the liquid discharge head of the present invention. It is a perspective view which shows one embodiment of the liquid discharge apparatus of this invention. It is a schematic diagram which shows the relationship between the target and shutter of a sputtering device used for the manufacturing method of the piezoelectric material of this invention. It is a schematic diagram which shows the relationship between the target and shutter of a sputtering device used for the manufacturing method of the piezoelectric material of this invention.

Explanation of symbols

41 Base 42 Diaphragm 43 Buffer Layer 44 Lower Electrode 45 Piezoelectric 46 Upper Electrode 51 Piezoelectric Element 52 Nozzle Plate 53 Discharge Port 61 Pressure Chamber (Individual Liquid Chamber)

Claims (11)

Perovskite oxide described by the general formula ABO ₃ (wherein the main component of the A site is Pb and the main component of the B site is Mg, Zn, Sc, In, Yb, Ni, Nb, Ti and Ta) A piezoelectric body having a laminated structure including at least three selected elements),
The laminated structure is
A layered first crystal phase having a crystal phase selected from tetragonal, rhombohedral, pseudocubic, orthorhombic or monoclinic;
A layered second crystal phase selected from tetragonal, rhombohedral, pseudocubic, orthorhombic or monoclinic and having a crystal phase different from the crystal phase of the first crystal phase;
A boundary layer between the first crystal phase and the second crystal phase, wherein the crystal phase gradually changes in the thickness direction of the layer;
A piezoelectric body characterized by having a single crystal structure or a uniaxially oriented crystal structure as a whole laminated structure. Perovskite oxide ABO ₃
(Pb _km α _lm ) _xm (Mg _mm Nb _nm Ti _om β _pm ) _ym O ₃
(In the formula, 1 ≦ xm / ym <1.5, km + lm = 1, 0.7 ≦ km ≦ 1, 0 ≦ lm ≦ 0.3, mm + nm + om + pm = 1, 0.1 <mm <0.3, 0. 3 <nm <0.5, 0.2 <om <0.4, 0 ≦ pm <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Sc, In, Yb, Ni, Ta, Co, W, Fe, Sn, or Zn.) The piezoelectric body according to claim 1, . Perovskite oxide ABO ₃
(Pb _kz α _lz ) _xz (Zn _mz Nb _nz Ti _oz β _pz ) _yz O ₃
(In the formula, 1 ≦ xz / yz <1.5, kz + lz = 1, 0.7 ≦ kz ≦ 1, 0 ≦ lz ≦ 0.3, mz + nz + oz + pz = 1, 0.2 <mz <0.4, 0. 5 <nz <0.7, 0.05 <oz <0.20, 0 ≦ pz <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Sc, In, Yb, Mg, Ta, Co, W, Fe, Sn, or Ni.) The piezoelectric body according to claim 1, . Perovskite oxide ABO ₃
(Pb _kn α _ln ) _xn (Ni _mn Nb _nn Ti _on β _pn ) _yn O ₃
(Where, 1 ≦ xn / yn <1.5, kn + ln = 1, 0.7 ≦ kn ≦ 1, 0 ≦ ln ≦ 0.3, mn + nn + on + pn = 1, 0.1 <mn <0.3,. 3 <nn <0.5, 0.3 <on <0.5, 0 ≦ pn <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents an element of any one of Pb, Sc, In, Yb, Mg, Ta, Co, W, Fe, Sn, or Zn). . Perovskite oxide ABO ₃
(Pb _kt α _lt ) _xt (Sc _mt Ta _nt Ti _ot β _pt ) _yt O ₃
(Where 1 ≦ xt / yt <1.5, kt + lt = 1, 0.7 ≦ kt ≦ 1, 0 ≦ lt ≦ 0.3, mt + nt + ot + pt = 1, 0.1 <mt <0.4, 0. 1 <nt <0.4, 0.3 <ot <0.5, 0 ≦ pt <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Nb, In, Yb, Mg, Ni, Co, W, Fe, Sn, or Zn.) The piezoelectric body according to claim 1, . Perovskite oxide ABO ₃
(Pb _ks α _ls ) _xs (Sc _ms Nb _{ns Tios} β _ps ) _ys O ₃
(Where 1 ≦ xs / ys <1.5, ks + ls = 1, 0.7 ≦ ks ≦ 1, 0 ≦ ls ≦ 0.3, ms + ns + os + ps = 1, 0.1 <ms <0.4, 0. 1 <ns <0.4, 0.3 <os <0.5, 0 ≦ ps <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Ta, In, Yb, Mg, Ni, Co, W, Fe, Sn, or Zn.) The piezoelectric body according to claim 1, . Perovskite oxide ABO ₃
(Pb _ky α _ly ) _xy (Yb _my Nb _ny T _oy β _py ) _yy O ₃
(Wherein 1 ≦ xy / yy <1.5, ky + ly = 1, 0.7 ≦ ky ≦ 1, 0 ≦ ly ≦ 0.3, my + ny + oy + py = 1, 0.1 <my <0.4, 0. 1 <ny <0.4, 0.4 <oy <0.6, 0 ≦ py <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Sc, In, Ta, Mg, Ni, Co, W, Fe, Sn, or Zn). . Perovskite oxide ABO ₃
(Pb _ki α _li ) _xi (In _mi Nb _ni Ti _oi β _pi ) _yi O ₃
(Where, 1 ≦ xi / yi <1.5, ki + li = 1, 0.7 ≦ ki ≦ 1, 0 ≦ li ≦ 0.3, mi + ni + oi + pi = 1, 0.2 <mi <0.4, 0. 2 <ni <0.4, 0.2 <oi <0.5, 0 ≦ pi <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Sc, In, Yb, Mg, Ni, Co, W, Fe, Sn, and Zn.) The piezoelectric body according to claim 1, wherein:   9. A piezoelectric element comprising: the piezoelectric body according to claim 1; and a pair of electrodes provided in contact with the piezoelectric body.   A liquid discharge head having an individual liquid chamber communicating with the discharge port and a piezoelectric element provided corresponding to the individual liquid chamber, and discharging the liquid in the individual liquid chamber from the discharge port; A liquid discharge head comprising the piezoelectric element according to claim 9 as the piezoelectric element.   A liquid discharge apparatus comprising the liquid discharge head according to claim 10.

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