JP4953351B2 - Perovskite oxide, piezoelectric element using the same, liquid discharge head, and liquid discharge apparatus - Google Patents

Description

The present invention relates perovskite oxide materials usable as the piezoelectric, and piezoelectric device using the same, a liquid ejecting head, and liquid discharge equipment.

  Piezoelectric materials have piezoelectric properties that convert electrical energy into mechanical energy, that is, mechanical displacement or stress or vibration, and vice versa. Such a piezoelectric material is used as a thin film. A piezoelectric element formed and sandwiched between electrodes is known. Piezoelectric elements that utilize the characteristics of piezoelectric bodies that generate displacement by applying an electric field and restore when the electric field is removed are used in motors, ultrasonic motors, transducers, actuators, etc. that require repeated operations. . Further, it is widely used in various fields such as inkjet printers, communication, biotechnology, medical care, automotive acceleration sensors, and measurement pressure sensors. With recent progress in MEMS (Micro Electro Mechanical System) technology, smaller and higher piezoelectric properties are desired.

  A piezoelectric material used for such a piezoelectric element is a PZT-based material discovered about 50 years ago. PZT-based materials have a sintering temperature of 1100 ° C. or higher, and sol-gel methods, sputtering methods, MBE methods, PLD methods, CVD methods, etc. are being developed as methods for forming PZT-based materials into thin films. However, a piezoelectric element made of a PZT material formed into a thin film by such a method has a problem that physical breakdown or the like easily occurs in the film or at the film interface. In particular, in MEMS, there is a need for a piezoelectric material that has improved uniformity and improved uniformity of piezoelectric properties by suppressing further improvements in piezoelectric properties and piezoelectric processing caused by fine processing in order to obtain finer and higher definition devices. Yes.

In addition, ceramic materials such as BaTiO ₃ and Pb (Zr, Ti) O ₃ are used as capacitor materials because of their high relative dielectric constants, but thin-film ceramic materials are required due to the demand for capacitor miniaturization. It has been. However, the relative dielectric constant of these ceramic materials is about 1500, and there is a possibility that sintering failure and a defect structure at the interface may occur as the film is thinned, and there is a possibility that characteristic failure will occur in a capacitor using these ceramic materials. There is.

  Such a piezoelectric material with improved piezoelectric characteristics and a manufacturing method thereof have been reported.

  Patent Document 1 discloses a piezoelectric ceramic including a rhombohedral perovskite structure compound, a tetragonal perovskite structure compound, and an orthorhombic perovskite structure compound.

Patent Document 2 discloses a single crystal composed of three or more elements selected from perovskite oxide ABO ₃ in which the main component of A is Pb and the main component of B is selected from Zn, Nb, and Ti.

Patent Document 3 discloses a method for producing a perovskite oxide thin film using a single crystal material as a substrate.
JP 2002-220280 A JP 2003-270602 A JP 2004-179642 A

  However, the piezoelectric ceramic disclosed in the above-mentioned Patent Document 1 is a mixture of perovskite structure compounds of each crystal system, and although the piezoelectric characteristics are improved, there are variations in characteristics and the thin film has sufficient uniformity. This is an issue.

  In addition, the existence of high-quality ceramics in the material of Patent Document 2 described above is not known. For this reason, when a thin film of a perovskite oxide is produced, it is very difficult to use a sputtering method using a perovskite oxide ceramic as a film formation target.

  Furthermore, the formation of the perovskite oxide by the ion beam assist method described in Patent Document 3 described above makes it difficult to produce a single crystal having a large area and increases the cost.

  An object of the present invention is to obtain a perovskite oxide having improved uniformity, high piezoelectric characteristics, strength even in a thin film, high adhesion, and excellent durability. In addition, it is possible to manufacture a large area perovskite type oxide, and it is possible to form a piezoelectric element using the oxide, a liquid discharge port with high density, a liquid discharge head having high discharge stability and landing accuracy, and liquid An object is to provide a discharge device.

The present invention relates to a perovskite oxide represented by ABO ₃ having a single crystal structure or a uniaxially oriented crystal structure, wherein the main component of the A site is Pb , and the B site is Zn, Mg, Nb, Sc, In , Yb, Ni, Ta and Ti, and having a plurality of crystal phases selected from tetragonal, rhombohedral, orthorhombic, cubic, pseudocubic and monoclinic, the perovskite-type oxide plurality of crystalline phase, characterized in that the oriented <100>, a piezoelectric element and a liquid ejecting head and a liquid discharge apparatus using the pre-Symbol perovskite oxide.

  The perovskite oxide of the present invention can provide a highly uniform perovskite oxide. As a result, the piezoelectric properties are high, and even a thin film has strength, high adhesion, and excellent durability.

  In addition, by using a powder material, it is possible to easily manufacture a perovskite oxide having a large area using a sputtering method.

The perovskite type oxide of this embodiment is a perovskite type oxide represented by ABO ₃ having a single crystal structure or a uniaxially oriented crystal structure, the main component of the A site is Pb , and the B site is Zn, Mg , Nb, Sc, In, Yb, Ni, Ta, and Ti, and includes a plurality of crystal phases. The crystal phase here means a crystal in which unit cells of any one of a tetragonal system, a rhombohedral system, an orthorhombic system, a cubic system, a pseudo cubic system, and a monoclinic system are connected. To do. Further, the plurality of crystal phases have a single crystal structure or a uniaxially oriented crystal structure in which the plurality of crystal phases are oriented in a single crystal axis direction in the <100> direction and are mutually incorporated. That is, as a perovskite type oxide, these two or more kinds of crystal phases are oriented in a single crystal axis direction in the <100> direction to form a single crystal structure or a uniaxial crystal structure. It is. The perovskite-type oxide of this embodiment is different from the one in which a plurality of crystal phases are included in a polycrystalline state with different crystal axis directions, and in a single perovskite-type oxide, There are a plurality of crystal phases, which are integrated into a single crystal. And the domain of this single crystal is very fine, in other words, each crystal phase constituting the single crystal is fine, and they exist uniformly in the single crystal structure, and the single crystal structure or uniaxial orientation A crystal structure is formed. For this reason, it can be suitably used as a material for an element that is very fine, such as MEMS, and requires uniformity such as piezoelectric characteristics.

  Examples of the single crystal axis direction of the single crystal structure of the perovskite oxide include <100>, which collectively refers to a total of six directions generally represented by [100], [010], and [001]. Here, in the case of a cubic system, the same crystal phase is obtained when oriented in the crystal axis direction [100] and oriented in [001]. On the other hand, in the case of tetragonal system, rhombohedral system, orthorhombic system, pseudo-cubic system, and monoclinic system, the crystal is oriented when oriented in the crystal axis direction [100] and oriented in [001]. The phases will be different. However, the perovskite oxide of this embodiment has a lattice constant close to that of a cubic system even in the case of tetragonal system, rhombohedral system, orthorhombic system, pseudo cubic system, and monoclinic system. The orientation of the crystal axis direction [100] and the orientation of [001] in the tetragonal system correspond to the orientation of the crystal axis direction [100] and the orientation of [001] in the cubic system, respectively. The orientation of the crystal axis direction [111] in the rhombohedral system and the orientation of [-1-1-1] also correspond to the orientation of the crystal axis direction [100] and the orientation of [111] in the cubic system, respectively. . Therefore, these orientations are collectively referred to as <100> and <111>. These crystal phases exist with their crystal axis directions oriented in the film thickness direction.

  As described above, the perovskite oxide of this embodiment has a <100> -oriented single crystal or a uniaxially oriented structure having a plurality of crystal phases, so that the material is uniform and has good film characteristics even in a fine region. Moreover, it is thought that a phase transition is easy to occur.

  It can be confirmed by using X-ray diffraction that the perovskite oxide film is oriented in a single crystal direction. For example, in the case of the PZT perovskite structure, the peak due to the piezoelectric film in the 2θ / θ measurement of X-ray diffraction is the (L00) plane (L = 1, 2, 3... {100}, {200}, etc. Only the peak of n: n is an integer) is detected.

  In the perovskite type oxide, the amount of the plurality of crystal phases may be any amount, but the ratio of each crystal phase peak intensity by X-ray diffraction accounts for tetragonal crystals with respect to the whole crystal. The proportion is preferably 5 to 90%. More preferably, it is 10 to 80%, and the piezoelectric characteristics can be enhanced.

[Specific examples of perovskite oxide]
Specific examples of the perovskite oxide (ABO ₃ ) include the following elemental compositions.

[1] PZNT-based perovskite oxides in which the A site contains Pb as a main component, the B site contains Nb, Zn, and Ti, and have a plurality of crystal phases.
[1-1] As the PZNT-based perovskite oxide, a perovskite oxide represented by (Pb _k , α _l ) _x (Zn _m , Nb _n , Ti _o , β _p ) _y O ₃ is preferable. In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.2 <m <0.4, 0.5 <N <0.7, 0.05 <o <0.2, 0 ≦ p <0.3. 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 Mg. The element of is shown.

[2] A multi-element system in which the A site contains Pb as a main component, and the B site contains at least three elements selected from Mg, Nb, Sc, In, Yb, Ni, Ta, or Ti, and has a plurality of crystal phases A perovskite type oxide can be mentioned.
[2-1] The perovskite oxide represented by (Pb _k , α _l ) _x (Mg _m , Nb _n , Ti _o , β _p ) _y O ₃ is preferable as the multielement perovskite oxide. In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.3, 0.3 <N <0.5, 0.2 <o <0.4, 0 ≦ p <0.3. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Sc, In, Yb, Ni, Ta, Co, W, Fe, or Sn. Indicates.

[2-2] The multi-element perovskite oxide is preferably a perovskite oxide represented by (Pb _k , α _l ) _x (Ni _m , Nb _n , Ti _o , β _p ) _y O ₃ . In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.3, 0.3 <N <0.5, 0.3 <o <0.5, 0 ≦ p <0.3 is satisfied. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Sc, In, Yb, Mg, Ta, Co, W, Fe, or Sn. Indicates.

The [2-3] above multi-component perovskite _{oxide, (Pb k, α l)} x (Sc m, Ta n, Ti o, β p) perovskite oxide represented by _y O ₃ is preferred. In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0.1 <N <0.4, 0.3 <o <0.5, 0 ≦ p <0.3. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Nb, In, Yb, Mg, Ni, Co, W, Fe, or Sn. Indicates.

[2-4] The multi-element perovskite oxide is preferably a perovskite oxide represented by (Pb _k , α _l ) _x (Sc _m , Nb _n , Ti _o , β _p ) _y O ₃ . In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0.1 <N <0.4, 0.3 <o <0.5, 0 ≦ p <0.3. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Ta, In, Yb, Mg, Ni, Co, W, Fe, or Sn. Indicates.

[2-5] The multi-element perovskite oxide is preferably a perovskite oxide represented by (Pb _k , α _l ) _x (Yb _m , Nb _n , Ti _o , β _p ) _y O ₃ . In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0.1 <N <0.4, 0.4 <o <0.6, 0 ≦ p <0.3. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Sc, In, Ta, Mg, Ni, Co, W, Fe, or Sn. Indicates.

[2-6] The multi-element perovskite oxide is preferably a perovskite oxide represented by (Pb _k , α _l ) _x (In _m , Nb _n , Ti _o , β _p ) _y O ₃ . In the formula, 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.2 <m <0.4, 0.2 <N <0.4, 0.2 <o <0.5, 0 ≦ p <0.3. And α represents any element of La, Ca, Ba, Sr, Bi, or Sb, and β represents any element of Pb, Sc, Yb, Ta, Mg, Ni, Co, W, Fe, or Sn. Indicates.

Since the perovskite oxide (ABO ₃ ) exemplified in the above [1] and [2] is located in the vicinity of the morphotropic phase boundary (commonly referred to as MPB), the perovskite oxide has a single crystal structure or a uniaxial crystal structure. In addition, it is considered that a plurality of crystal phases can be included. As a result, the uniformity of the film is good, the piezoelectric characteristics are high, and the dielectric constant is high.

  In addition, the Pb element may be contained as both an A site component and a B site component, but when contained as an A site component, a divalent metal, and when contained as a B site component, a tetravalent metal. Contained as.

  As the perovskite oxide of this embodiment, a film-like oxide is preferable because of high film strength and adhesion. In the case of a film, a film having a film thickness of 1 μm or more and 10 μm or less is preferable because it is a sufficient thickness as an actuator in MEMS and can be manufactured by an epitaxial film formation process.

In addition, there is a material in which a relaxor PbZnNbO ₃ material having an elemental composition approximate to the elemental composition of the above-mentioned [1] PZNT perovskite oxide and PbTiO ₃ are mixed. However, this material does not correspond to the perovskite oxide in which the crystal phases are mixed according to this embodiment because the grain boundaries exist in a polycrystalline state in which a plurality of crystal phases are different from each other in the crystal axis direction. .

  In addition, in the above [2] multi-element perovskite type oxide, the following ones having high piezoelectricity can be cited as those having an elemental composition that approximates such an elemental composition.

Mixing of relaxor PbMgNbO ₃ material and PbTiO ₃ . Mixing of relaxor PbNiNbO ₃ material and PbTiO ₃ . Mixing of relaxor-based PbScTaO ₃ material and PbTiO ₃ . Mixing of relaxor PbScNbO ₃ material and PbTiO ₃ . Mixing of relaxor PbYbNbO ₃ material and PbTiO ₃ . Mixing of relaxor-based PbInNbO ₃ material and PbTiO ₃ .

  However, in any of the relaxer-based mixtures described above, the elemental composition of the perovskite oxide of this embodiment is not included, and a plurality of crystal phases have different crystal axis directions, and there are grain boundaries in a polycrystalline state. Therefore, it does not correspond to the perovskite oxide in which the crystal phase of the present embodiment is mixed. Moreover, only the bulk body is known for the above-mentioned relaxer-based mixture. Therefore, in order to use it for the actuator of MEMS etc., since a bulk is cut out and used as a thin piece, manufacture becomes very difficult.

  On the other hand, since the perovskite oxide of this embodiment is a <100> -oriented single crystal or uniaxially oriented structure having a plurality of crystal phases, the material can be formed uniformly and with good film characteristics even in a fine region, and MEMS. It can also be suitably used for the actuator of the above.

[Production method of perovskite oxide]
In the method for producing a perovskite oxide according to this embodiment, high temperature heating sputtering is performed using a target filled with a powdery raw material mixed at a mixing ratio that is an elemental composition ratio of the perovskite oxide to be formed. Can be manufactured.

Specifically, the metal oxide powder is sufficiently mixed so that the composition ratio is the same as the elemental composition ratio of the target perovskite oxide represented by ABO ₃ , and a raw material mixture is prepared and used as a target. .

For example, when the PZNT-based perovskite oxide exemplified in [1-1] above is formed on a substrate, powders such as PbO ₂ , ZnO, Nb ₂ O ₅ , PbTiO ₃ , La ₂ O ₃ , and SrO are used. Can be used to prepare the raw material mixture.

  Such a raw material mixture is filled in a stainless steel dish for a sputtering target uniformly so as not to have a gap, thereby obtaining a sputtering target.

Using this sputtering target, high-temperature heat sputtering is performed, and a single crystal or a uniaxial crystal including two or more crystal phases selected from tetragonal, rhombohedral, orthorhombic, cubic, pseudocubic and monoclinic An oriented crystal oxide film can be obtained on a single crystal substrate such as SrTiO ₃ (100). The temperature in high-temperature heat sputtering is preferably 500 ° C to 700 ° C. At 600 ° C. or higher, Pb is easily removed, so 500 ° C. to 600 ° C. is more preferable.

  The PZNT-based perovskite oxide is difficult to obtain by sputtering because it is difficult to obtain a ceramic material generally used as a sputtering target. However, as in the method for producing a perovskite oxide according to this embodiment, by preparing a powder and using it as a target, spattering is possible even in the case of a material that does not have a ceramic material as a target. The area can be greatly expanded. In addition, it is easier to prepare a composition ratio for obtaining a target material when a powder material is prepared than when a ceramic material is used as a target.

In addition, the multi-component perovskite oxide exemplified in the above [2-1] is prepared by using a powder of PbO ₂ , MgO, Nb ₂ O ₅ , PbTiO ₃ , La ₂ O ₃ , SrO or the like. The film can be formed by the method as described above.

[Piezoelectric element]
The piezoelectric element of this embodiment is not particularly limited as long as it has a piezoelectric layer containing the perovskite oxide of the present embodiment and a pair of electrodes in contact with the piezoelectric layer. . Such a piezoelectric element is restored by being applied to a pair of electrodes, causing the piezoelectric layer to be displaced, and removing the application.

  As an example of such a piezoelectric element of this embodiment, for example, as shown in FIG. 1, it is sandwiched between a lower electrode 16 and an upper electrode 18 that are a pair of electrodes on a base 20 via a diaphragm 15. Further, there can be mentioned those having a laminated structure in which the piezoelectric films 10 having the piezoelectric bodies 17 are laminated. A buffer layer 19 for adjusting the crystal structure may be provided between the vibration plate 15 and the piezoelectric film 10.

The material of the substrate in the piezoelectric element of the present embodiment is preferably a material having good crystallinity, such as Si, and specifically, SOI or the like in which a SiO ₂ film is formed on Si. 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. As thickness of a vibrating body, 0.5-10 micrometers can be mentioned, for example, Preferably it is 1.0-6.0 micrometers. This thickness includes the thickness of the buffer layer when the buffer layer is provided.

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 19 or may be provided between the diaphragm 15 and the buffer layer 19. 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 has an adhesion layer for improving adhesion to the diaphragm. A multilayer structure can also be used. As the material of the lower electrode, a metal material or an oxide material can be used. Examples of the metal material include Au, Pt, Ni, Cr, Ir, and the like, and a laminate of Ti, Ta, Pb, and the like can also be used. Examples of the oxide material include SrTiO ₃ , SrRuO ₃ , IrO ₂ , BaPbO ₃ , RuO ₂ , and Pb ₂ Ir ₂ O ₇ doped with La and Nb. Either one of the pair of electrodes preferably has a crystal structure. 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 preferred orientation crystal orientation of the substrate surface is preferably <100>. When the preferential orientation crystal orientation of the substrate surface of the lower electrode is <100>, the preferential orientation crystal orientation of the laminated piezoelectric body 45 is oriented in the <100> direction.

  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 crystallinity of the piezoelectric body provided thereon can be made good. 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.

  The thickness of the lower electrode is preferably 50 to 400 nm, more preferably 80 to 200 nm.

  The piezoelectric body used in the piezoelectric element of this embodiment is the piezoelectric body of this 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 piezoelectric film thickness is 100 nm or more, when the piezoelectric element is used in the inkjet head M or the like, it has durability against stress generated by repeated driving, and if it is 10 μm or less, film peeling occurs. Can be suppressed.

  The upper electrode 18 is provided immediately above the piezoelectric body 17 and charges the piezoelectric body together with the lower electrode. The upper electrode may be provided on the piezoelectric body through an adhesion layer made of the same material as the adhesion layer provided between the lower electrode and the diaphragm. The upper electrode may be the same as or different from the lower electrode in material and configuration. In the liquid discharge head, one may be a common electrode and the other may be a drive electrode.

[Method for Manufacturing Piezoelectric Element]
Such a method of manufacturing a piezoelectric element according to this embodiment includes a step of forming a piezoelectric layer on one electrode by using the method for manufacturing a perovskite oxide material, and the other on the piezoelectric layer. A method having a step of forming the electrode can be mentioned as a preferable method.

  As a method for manufacturing the electrode, thin film manufacturing techniques such as sputtering, CVD, laser ablation, and MBE can be used. By these methods, the electrode material can be formed as a film having a specific crystal structure with the electrode material oriented in a specific direction.

[Liquid discharge head]
The liquid discharge head according to the present embodiment includes an individual liquid chamber communicating with the discharge port and a piezoelectric element provided corresponding to the individual liquid chamber, and discharges the liquid in the individual liquid chamber from the discharge port. A liquid discharge head that uses the piezoelectric element. Since the liquid discharge head according to this embodiment includes the piezoelectric element, a liquid discharge apparatus using the piezoelectric element has excellent liquid discharge characteristics and excellent performance.

  As shown in FIG. 2, the inkjet head as an example of the liquid discharge head of the present embodiment includes a plurality of individual liquid chambers 13 connected to a common liquid chamber 14 that stores ink, An ejection port 11 is provided through the communication hole 12 for ejecting ink. A diaphragm 15 is provided to form the ceiling of the individual liquid chamber 13, and a lower electrode 16 and an upper electrode 18 (one pair) provided directly or via a buffer layer without providing a buffer layer on the diaphragm. The piezoelectric element 10 including the piezoelectric body 17 sandwiched between the electrodes) is provided.

The piezoelectric element 10 is one to which the piezoelectric element of the present embodiment is applied, and the one shown in FIG. 1 can be exemplified. The material of the diaphragm 15 in such a piezoelectric element is preferably an oxide such as ZrO ₂ , BaTiO ₃ , MgO, SrTiO ₃ , MgAl ₂ O ₄ and / or Si doped with rare earth elements including Sc and Y. Si may contain a dopant element such as a B element. The diaphragm 15 mainly composed of these materials preferably has a specific crystal structure, and the crystal structure of (100), (110) or (111) is oriented with an intensity of 80% or more. More preferably, it is 99% or more and 100% oriented. Here, “99% orientation” means that there is less than 1% of crystals with an orientation different from the main orientation in XRD intensity.

  The material of the buffer layer 19 is preferably a material whose lattice constant is within a range of 8% or less of the lattice constant of the substrate. The buffer layer 19 is preferably an oxide that can be formed by sputtering, MO-CVD, or laser ablation. For example, the buffer layer 19 is cubic or pseudo-rectangular and has a lattice constant of 3.6 to 6.0 angstroms. Those having the following crystal structure are preferred.

As a specific configuration, for example, 10% Y ₂ O ₃ —ZrO ₂ (100) / Si (100), 10% Y ₂ O ₃ —ZrO ₂ (111) / Si (111), SrTiO ₃ (100) / MgO (100), MgAl ₂ O ₄ (100) / MgO (100), BaTiO ₃ (100) / MgO (100), and the like. Here, the lattice constant of 10% Y ₂ O ₃ —ZO ₂ is 5.16 Å, the lattice constant of SrTiO ₃ is 3.91 Å, and the lattice constant of MgO is 4.21 Å. The lattice constant of MgAl ₂ O ₄ is 4.04 Å, the lattice constant of BaTiO ₃ is 3.99 Å, and the lattice constant of Si is 5.43 Å. When the lattice constant matching is calculated, for example, 10% Y ₂ O ₃ —ZrO ₂ (111) / Si (111) is taken as an example. 10% Y ₂ O ₃ —ZrO ₂ (111) / Si (111) is 5.16 × √2 = 7.30Å, Si (111) is 5.43 × √2 = 7.68Å, and there is a difference in consistency. Is 4.9%, which shows that it is good.

The material of the upper electrode and the lower electrode can be the same as the electrode of the piezoelectric element. In particular, as a material of the lower electrode 16 provided on the buffer layer 19, when the material of the buffer layer is 10% Y ₂ O ₃ —ZrO ₂ (111), Pt (100), Ir (100), SrRuO ₃ (100), Sr _0.96 La _0.04 TiO ₃ (100), Sr _0.97 Nb _0.03 TiO ₃ (100), BaPbO ₃ (100), and the like. When the material of the buffer layer is SrTiO ₃ (100), Pt (100), Ir (100), SrRuO ₃ (100), Sr _0.97 La _0.03 TiO ₃ (100), Sr _0.97 Nb _0.03 TiO ₃ (100), BaPbO ₃ (100) and the like can be mentioned. When the material of the buffer layer is BaTiO ₃ (001) or MgAl ₂ O ₄ (100), a film such as (100) can be cited.

In addition, as a material of the lower electrode 16 when the buffer layer 19 is directly provided on the vibration plate 15, for example, SrRuO ₃ (100) / SrTiO ₃ (100), Pt (100) / MgO (100), Ir (100) / MgO (100), Ru (100) / MgO (100), etc. can be mentioned.

  The shape of the upper electrode and the lower electrode may be any shape, but the lower electrode may be provided so as to be drawn out to a portion larger than the piezoelectric body and not provided with the piezoelectric body. Further, the upper electrode may be provided so as to be drawn out on the opposite side of the lower electrode and connected to a driving power source (not shown).

  Examples of the piezoelectric body include those similar to the piezoelectric body in the piezoelectric element, and the shape of the top surface is rectangular, but any shape such as an ellipse, a circle, a parallelogram, etc. The cross-sectional shape may be rectangular, trapezoidal, inverted trapezoidal, or the like.

  The width Wa of the individual liquid chamber 13 in the above-described ink jet head is preferably 30 to 180 μm as shown in the schematic structural diagram of FIG. 3 as an inkjet unit, and the length Wb depends on the amount of ejected liquid droplets. 3 to 6.0 mm is preferable. The discharge port 11 may have a circular shape or a star shape, and its diameter is preferably 7 to 30 μm, and is connected to the communication hole 12 having a larger diameter than the communication hole 12 with a tapered portion. can do. The length of the communication hole 12 is preferably 0.05 to 0.5 mm. Within this range, the droplets can be discharged while maintaining a constant speed with no variation in the discharge amount.

  The liquid discharge head according to this embodiment discharges the liquid in the individual liquid chamber 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. Since the piezoelectric characteristics of the piezoelectric body are high, the liquid can be uniformly ejected at a high speed in the liquid ejection head, and the individual liquid chambers can be provided at a high density, thereby reducing the size.

The liquid discharge head of this embodiment can be applied to a liquid discharge portion of an apparatus that discharges various liquids in addition to an inkjet head.
[Liquid discharge head manufacturing method]
The method of manufacturing the liquid discharge head according to this embodiment includes forming a diaphragm on a substrate, forming a lower electrode on the diaphragm, and using the method for manufacturing the perovskite oxide material on the lower electrode, a piezoelectric layer. And forming an upper electrode on the piezoelectric layer.

(Formation of diaphragm)
As a method for forming the diaphragm 15 on the substrate 20, a thin film production method such as a sputtering method, a CVD method, a laser ablation method, or an MBE method can be used. In particular, the sputtering method is preferable because an oxide thin film epitaxially grown on the substrate 20 can be obtained by sufficiently heating the deposition substrate during heating.

In addition, the buffer layer 19, the lower electrode layer 16, the piezoelectric layer 17, and the upper electrode 18 are formed on the upper layer of Si or SiO ₂ which is a film formation substrate, or are sliced before or before forming, and are used as the diaphragm 15 May be. In particular, when the base material is SOI, an SiO ₂ layer as an insulating layer and an upper Si single crystal layer can be used as the diaphragm 15.

(Formation of buffer layer)
Next, if necessary, a buffer layer 19 for adjusting the crystal orientation for making the crystal orientation of the upper electrode a desired orientation is formed on the vibration plate 15. As a method for forming the buffer layer 19, a thin film production method such as sputtering, CVD, laser ablation, or MBE can be used. By these methods, it is possible to form a film on the diaphragm 15 with the buffer layer material oriented in a specific direction. Here, in using the film formation method, it is preferable to heat the substrate during film formation to, for example, 500 ° C. to 850 ° C. When the diaphragm 15 itself plays the role of the buffer layer 19 of the base body 20 and the lower electrode 16, the buffer layer 19 need not be formed again.

(Method of forming electrode)
As a method of forming the lower electrode 16 on the vibration plate 15 (on the buffer layer 19 when the buffer layer 19 is provided), a thin film manufacturing method such as sputtering, CVD, laser ablation, or MBE is used. Can do. In particular, the sputtering method is preferable because an oxide thin film epitaxially grown on the buffer layer 19 or the substrate 20 can be obtained by sufficiently heating the deposition substrate during heating, for example, by heating to 500 ° C. to 700 ° C. .

  The shape of the lower electrode 16 may be the pattern shown in FIG.

  This upper electrode can also be formed on the piezoelectric layer 17 by the same method as the formation of the lower electrode.

(Individual liquid chamber molding method)
Next, a method for forming the individual liquid chamber of the liquid discharge head according to this embodiment will be described. A method in which the individual liquid chamber 13 is provided in the substrate 20 on which the piezoelectric element is formed by the above-described method, or an individual liquid chamber is provided in another substrate (not shown) and attached to the substrate in which the piezoelectric element is manufactured. And the like.

  As a method of forming the individual liquid chamber, a method of forming a recess in a part of the base body 20 provided with the piezoelectric element by wet etching, dry etching, sand mill or the like can be used. For example, as shown in the bottom view of the liquid discharge head in FIG. 4, a plurality of concave portions (inside the broken line portions) that form the individual liquid chambers 13 in a staggered arrangement with a constant pitch number are illustrated with respect to the piezoelectric element 10. It forms so that it may become arrangement. After that, as shown in FIG. 5, the nozzle plate 21 having the discharge ports 11 drilled corresponding to the recesses formed in the base body 20 is joined. Or the nozzle plate which formed the discharge outlet 11 and the communicating hole can be joined. By forming the individual liquid chamber 13 and the piezoelectric element 10 in the illustrated arrangement, it is preferable because pressure can be appropriately applied to the individual liquid chamber 13 by displacement of the piezoelectric body. Further, when forming the recesses in the base body, anisotropic etching by wet etching with an alkaline solution may be performed using a (110) oriented silicon substrate to form recesses having a parallelogram upper surface. When the upper surface shape of the individual liquid chambers arranged in a staggered manner is a parallelogram, the discharge ports 11 and 11 ′ provided in each individual liquid chamber can be arranged with a short interval. In this case, the upper surface shape of the piezoelectric element is If it is a parallelogram, the individual liquid chambers can be arranged with high density.

As a method of drilling an ink ejection port and a communication hole in the nozzle plate 21, etching, machining, and laser beam irradiation can be used. The material of the nozzle plate that forms the discharge port 11 may be the same as or different from that of the base body 20 that forms the piezoelectric element. In this case, the difference in thermal expansion coefficient between the piezoelectric element and the substrate 20 is different. 1 × 10 ⁻⁶ to 1 × 10 ⁻⁸ ° C., for example, SUS, Ni and the like are preferable.

  As a method for bonding the base body 20 and the nozzle plate, an organic adhesive may be used, but a metal bonding method using an inorganic material is preferable. As a material used for metal bonding, a material capable of bonding these substrates at a low temperature of 250 ° C. or lower is preferable. This is because even if it is long, the difference in thermal expansion coefficient with the substrate is small and problems such as warping of the element can be avoided, and damage to the piezoelectric element can be suppressed. . Specific examples of materials used for such metal bonding include In, Au, Cu, Ni, Pb, Ti, and Cr.

[Liquid discharge device]
The liquid ejection apparatus according to this embodiment may be any apparatus having the above-described liquid ejection head, and an example thereof is an ink jet recording apparatus. For example, there may be mentioned one having the operation mechanism portion shown in FIG. 7 in a state in which the exteriors 82 to 85 and 87 of the ink jet recording apparatus 81 shown in FIG. 6 are removed. As shown in FIG. 7, in the ink jet recording apparatus, an automatic feeding unit 97 that automatically feeds a recording sheet as a recording medium into the apparatus main body 96, and a recording sheet that is sent out from the automatic feeding unit 97 are set in a predetermined manner. A transport unit 99 is provided that guides the recording position to the discharge port 98 from the recording position. Furthermore, a recording unit 91 that performs recording on the recording paper conveyed to the recording position, and a recovery unit 90 that performs recovery processing on the recording unit 91 are provided. The recording unit 91 is provided with a carriage 92 that houses the liquid ejection head of this embodiment and is reciprocated on the rail.

  The operation of such an ink jet recording apparatus will be described. The carriage 92 moves on the rail and discharges the liquid by an electrical signal sent from a separately connected computer. The liquid is ejected by applying a driving voltage to the electrodes sandwiching the piezoelectric body, pressurizing each individual liquid chamber via the vibration plate 15 by the displacement of the piezoelectric body, and ejecting ink from the ejection port 11. As a result, the intended printing or the like is performed.

  In the liquid ejection apparatus of this embodiment, droplets can be ejected uniformly at a high speed, and the apparatus can be miniaturized.

  Although the above example shows an example of a printer, the liquid discharge apparatus can be used for an inkjet recording apparatus such as a facsimile, a multifunction peripheral, a copying machine, or an industrial discharge apparatus.

[Example 1]
The production of the liquid ejection head of this embodiment will be specifically described with reference to examples.

First, a (100) -oriented Si substrate was used for the main body substrate portion (base 20). Using a sputtering apparatus (L-210-FH (manufactured by ANELVA)) on a Si substrate, stabilized zirconia YSZ (Y ₂ O ₃ —ZrO ₂ ) functioning as the diaphragm 15 and the buffer layer 19 is (100) oriented. A film was formed. The film forming conditions of the diaphragm 15 and the buffer layer 19 are as follows: the Si substrate is heated to 800 ° C., Ar and O ₂ are used as the ionizing gas, the applied power between the substrate and the target is 60 W, and the pressure in the apparatus is 1 The epitaxial crystal was grown at 0.0 Pa. As a result, to obtain a diaphragm having a thickness of 200nm (100) first axis orientation.

  Next, similarly to the method of forming the diaphragm 15, the Pt lower electrode 16 was produced on the diaphragm. As an electrode manufacturing method, Pt was used as the target, the substrate temperature was 600 ° C., ionized gas Ar was used, the applied power between the diaphragm and the target was 100 W, and the pressure in the apparatus was 0.5 Pa. As a result, a Pt film having a thickness of 400 nm and a (100) single crystal was obtained by epitaxial crystal growth.

A piezoelectric body 17 was produced on the lower electrode using the sputtering apparatus. As a method for producing the piezoelectric body 17, powder prepared by preparing oxides PbO, ZnO, Nb ₂ O ₅ , PbTiO _{3 and the} like so as to have the following target composition is put in a pot mill. About 50 magnetic balls having a diameter of 15 mm were put into this, and pulverized and mixed by rotating on a mill at a rotational speed of 300 rpm. Further, the pulverized and mixed powder was put together with glass beads having a diameter of 1 mm and a dispersion in a paint shaker container and sufficiently dispersed at 640 rpm. Next, the glass beads were removed, and the dispersion was removed with an evaporator to obtain a powder material for a sputtering target. <Target composition 1>
In (Pb _k , α _l ) _x (Zn _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k + 1 = 1, k = 1, l = 0, m + n + o + p = 1, m = 0.22, n = 0.44, o = 0.33, p = 0
The sputtering target powder material thus prepared was uniformly filled in the sputtering target stainless steel pan so that there was no gap, and a sputtering target was prepared. High-temperature heat sputtering was performed in the same manner as the diaphragm and electrode film formation. 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. With a sputtering time of 420 min, a (100) -oriented single crystal piezoelectric body with a tetragonal crystal and rhombohedral crystal mixed phase was obtained. The crystal phase was confirmed using XRD and TEM.

  The upper electrode 18 was produced by the same method as the production method of the lower electrode. Pt is used as a target, substrate temperature is 600 ° C., 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 thick Pt film was obtained.

Next, the Si substrate was subjected to a drite etching method using ICP from the surface opposite to the surface on which the diaphragm 15 was provided to remove the central portion serving as the individual liquid chamber 13 to form a recess. The substrate temperature was 20 ° C., the gases used were SF ₆ and C ₄ F ₈ , the high-frequency coil dielectric was 1800 W in RF, and the pressure in the apparatus was 4.0 Pa. An individual liquid chamber 13 was fabricated by bonding an Si nozzle plate 21 having the ejection port 11 to an Si substrate by an Si-Si bonding method, and a liquid ejection head M in which the piezoelectric elements 10 were connected was fabricated. The length of the vibration part of each piezoelectric element 10 was 5000 μm, and the width was 100 μm.
[Example 2]
In the production of the piezoelectric body, a liquid discharge head was produced in the same manner as in Example 1 except that the piezoelectric body was produced using oxides PbO, MgO, Nb ₂ O ₅ , PbTiO _{3 and the} like with the following target compositions. did.
<Target composition 2>
(Pb _k , α _l ) _x (Mg _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.22, n = 0.44, o = 0.33, p = 0
The piezoelectric body obtained by the above method was a (100) -oriented single crystal piezoelectric body in which pseudo cubic crystals and tetragonal crystals were mixed.

[Example 3]
In the production of the piezoelectric body, a liquid discharge head was produced in the same manner as in Example 1 except that the piezoelectric body was produced using oxides PbO, NiO, Nb ₂ O ₅ , PbTiO _{3 and the} like with the following target compositions. did.
<Target composition 3>
(Pb _k , α _l ) _x (Ni _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.20, n = 0.40, o = 0.40, p = 0
The piezoelectric body obtained by the above method was a (100) -oriented single crystal piezoelectric body in which pseudo cubic crystals and tetragonal crystals were mixed.

[Example 4]
In the production of the piezoelectric material, liquid ejection was performed in the same manner as in Example 1 except that the piezoelectric material was produced using oxides PbO, Sc ₂ O ₃ , Ta ₂ O ₅ , PbTiO _{3 and the} like with the following target compositions. A head was produced.
<Target composition 4>
_{(Pb k, α l) x} (Sc m, Ta n, Ti o, β p) in _{y O 3, 1 ≦ x /} y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.275, n = 0.275, o = 0.45, p = 0
The piezoelectric body obtained by the above method was a (100) -oriented single crystal piezoelectric body in which pseudo cubic crystals and tetragonal crystals were mixed.

[Example 5]
In the production of the piezoelectric material, liquid ejection was performed in the same manner as in Example 1 except that the piezoelectric material was produced using oxides PbO, Sc ₂ O ₃ , Nb ₂ O ₅ , PbTiO _{3 and the} like with the following target compositions. A head was produced.
<Target composition 5>
(Pb _k , α _l ) _x (Sc _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.275, n = 0.275, o = 0.45, p = 0
The piezoelectric body obtained by the above method was a (100) -oriented single crystal piezoelectric body in which rhombohedral and tetragonal crystals were mixed.

[Example 6]
In the production of the piezoelectric material, liquid ejection was performed in the same manner as in Example 1 except that the piezoelectric material was produced using oxides PbO, Yb ₂ O ₃ , Nb ₂ O ₅ , PbTiO _{3 and the} like with the target composition as follows. A head was produced.
<Target composition 6>
(Pb _k , α _l ) _x (Yb _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.25, n = 0.25, o = 0.50, p = 0
The piezoelectric body obtained by the above method was a (100) -oriented single crystal piezoelectric body in which monoclinic crystals and tetragonal crystals were mixed.

[Example 7]
In the production of the piezoelectric material, liquid ejection was performed in the same manner as in Example 1 except that the piezoelectric material was produced using the oxide PbO, In ₂ O ₃ , Nb ₂ O ₅ , PbTiO _{3 and the} like with the target composition as follows. A head was produced.
<Target composition 7>
In (Pb _k , α _l ) _x (In _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.32, n = 0.32, o = 0.37, p = 0
The piezoelectric body obtained by the above method was a single crystal piezoelectric body in which pseudo cubic crystals and tetragonal crystals were (100) -oriented.

[Comparative Example 1]
In the production of the piezoelectric body, a liquid discharge head was produced in the same manner as in Example 1 except that the piezoelectric body was produced using oxides PbO, MgO, Nb ₂ O ₅ , PbTiO _{3 and the} like with the following target compositions. .
<Target composition / Comparison 1>
(Pb _k , α _l ) _x (Mg _m , Nb _n , Ti _o , β _p ) _y O ₃ , 1 ≦ x / y <1.2, k = 1, l = 0, m + n + o + p = 1, m = 0.20, n = 0.40, o = 0.10, p = 0
The piezoelectric body obtained by the above method was a pseudo cubic single crystal.

[Comparative Example 2]
In the production of the piezoelectric material, liquid ejection was performed in the same manner as in Example 1 except that the piezoelectric material was produced using oxides PbO, ZrO ₃ , PbTiO _{3 and the} like and the target composition as Pb ₁₁₀ (Zr ₅₀ , Ti ₅₀ ) O _3. A head was produced.

  The piezoelectric body obtained by the above method was a tetragonal single crystal.

[Comparative Example 3]
In the production of the piezoelectric body, a ceramic having a composition of Pb ₁₁₀ (Zr ₅₆ , Ti ₄₄ ) O ₃ was used as a target, and an amorphous film was formed on the lower electrode at room temperature, and then in an oxygen atmosphere at 700 ° C. The baking was performed for 5 hours. The produced piezoelectric body was <100> preferentially oriented. Otherwise, a liquid discharge head was produced in the same manner as in Example 1. The obtained piezoelectric body was a rhombohedral single crystal.

  Further, in each of the above examples and comparative examples, an example of a single crystal has been shown, but by changing the film formation conditions, a film below the piezoelectric film, for example, stabilized zirconia YSZ is uniaxially oriented, so that <100> A uniaxially oriented piezoelectric film can be obtained.

[Structural analysis]
The method for confirming the state of the crystal phase described above in the state of structural analysis will be described with reference to Example 2.

  The details of confirmation of the state of the crystal phase of the single crystal perovskite oxide produced in Example 2 are shown.

  For this confirmation, the macro state was analyzed by X-ray diffraction and the micro state was analyzed by TEM. FIG. 8 shows a reciprocal lattice space map by X-ray diffraction of the single crystal perovskite type oxide material produced in Example 2. In FIG. 8, the left side is a symmetric surface (200), and the right side is an asymmetric surface (204). According to this, there are two peaks, i.e., a peak indicating that the a and b axis lengths are equal, and a peak indicating that the a and b axis lengths are different. I understand.

  Similarly, it was confirmed that the piezoelectric element of Example 1 had a piezoelectric body having tetragonal crystals and rhombohedral crystals.

  For comparison, FIGS. 9 and 10 show reciprocal lattice space maps of the single crystal perovskite oxides produced in Comparative Example 1 and Comparative Example 3, respectively. In FIG. 9, the left side is a symmetric surface (200), and the right side is an asymmetric surface (204). According to this, it can be seen that only a peak indicating that the a-axis and b-axis lengths are equal exists, so that it exists in a rhombohedral single phase. Further, in Comparative Example 3 of FIG. 10, similarly, the left is a symmetric plane (200) and the right is an asymmetric plane (204), but there are also only peaks indicating that the a and b axis lengths are different. From this, it can be seen that it exists in a tetragonal single phase. Similarly, it was confirmed that the piezoelectric element of Comparative Example 2 was composed of a single phase of PZT tetragonal crystal.

  As an evaluation of the micro state, FIG. 11 shows a TEM image of the single crystal perovskite oxide produced in Example 2. According to this, a band-like contrast forming an angle of about 45 ° with the substrate interface was observed. Therefore, microscopic electron diffraction was performed within the band-like contrast. The result is shown in FIG. From FIG. 12, a spot or a plurality of spots extending in the direction perpendicular to the growth direction was observed. As a result, it can be seen that there are domains having different face spacings. That is, it shows that a plurality of crystal phases exist in a minute region having a beam spot diameter of 50 nm.

[Evaluation]
[Piezoelectric displacement]
About the obtained liquid discharge head, the displacement amount of the piezoelectric element when a voltage was applied with an applied voltage of 20 V and 10 kHz was measured with a laser Doppler displacement meter. The results are shown in Table 1.

  From the results, it can be seen that the displacement amounts of the piezoelectric elements of Examples 1 to 7 are significantly larger than those of Comparative Examples 1 to 3.

[Accuracy of landing in liquid discharge head]
The droplet landing accuracy is based on a measurement value obtained by measuring the deflection of the droplet dot on the recording medium when an ink having a viscosity of 10 cps is applied and a voltage is applied at an applied voltage of 20 V and 10 kHz, using a landing accuracy measuring machine. evaluated. In the evaluation method, a specific pattern was measured five times, and the deflection measurement accuracy (X deflection accuracy (μm), Y deflection accuracy (μm)) was obtained from the worst value of 3σ at each measurement position. Less than 0.1 μm was rated as “◎”, 0.1 μm or more and less than 0.2 μm as ◯, 0.2 μm or more and less than 0.3 μm as Δ, and 0.3 or more as x. The results are shown in Table 2.

  As a result, in the liquid ejection head of the example, the landing accuracy of the deflection measurement accuracy was less than 0.1, whereas in Comparative Example 1, the landing accuracy of the deflection measurement accuracy was 0.1 μm or more and less than 0.2 μm. In Comparative Examples 2 and 3, the landing accuracy was 0.2 μm or more and less than 0.3 μm. From this result, it was found that the liquid discharge head of this embodiment has high stability and reliability.

  By adopting the form as described above, piezoelectric characteristics are high, and even a thin film has strength, high adhesion, excellent durability, and stable piezoelectric characteristics. A perovskite type oxide used for a capacitor having a specific dielectric constant can be obtained.

  In addition, since the thin film exhibits excellent piezoelectric characteristics, the piezoelectric characteristics can be obtained even when the element is downsized, so that high-density arrangement is possible.

  In addition, a perovskite oxide having a large area can be easily manufactured at low cost by using an epitaxial film forming process, and can be used for a MEMS device or the like.

  Furthermore, it can be easily manufactured by using an epitaxial film formation process, and when formed into a thin film, the film strength is high and the adhesiveness with the electrode component is high. And can have excellent durability. By using such a piezoelectric element, it is possible to form a high-density liquid discharge head. In addition, since the piezoelectric characteristics are good and the durability is high, it is possible to obtain a liquid ejection apparatus of high quality with high ejection stability and landing accuracy.

It is a figure which shows the partial cross section perspective view which shows an example of the piezoelectric material element of this invention. It is a figure which shows the schematic diagram of the principal part of an example of the liquid discharge head of this invention. It is a figure which shows the fragmentary top view of an example of the liquid discharge head of this invention. It is a figure which shows the fragmentary top view of an example of the liquid discharge head of this invention. It is a figure which shows the external appearance perspective view of an example of the liquid discharge head of this invention. It is a figure which shows the schematic of the external appearance of an example of the liquid discharge apparatus of this invention. It is a figure which shows the schematic of the internal operation | movement mechanism part of an example of the liquid discharge apparatus of this invention. 4 is a diagram showing a reciprocal lattice space map by X-ray diffraction of a perovskite oxide produced in Example 2. FIG. 6 is a diagram showing a reciprocal lattice space map by X-ray diffraction of a perovskite oxide produced in Comparative Example 1. FIG. 6 is a diagram showing a reciprocal lattice space map by X-ray diffraction of a perovskite oxide produced in Comparative Example 1. FIG. 4 is a diagram showing a TEM image of a perovskite oxide produced in Example 2. FIG. FIG. 6 is a diagram showing a microscopic electron diffraction pattern of a portion where a band-like contrast was observed in a TEM image of the perovskite oxide produced in Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Piezoelectric element 11, 11 'Ejection port 12 Communication hole 13 Individual liquid chamber 14 Common liquid chamber 15 Diaphragm 16 Lower electrode 17 Piezoelectric layer 18 Upper electrode 19 Buffer layer 20 Base 21 Nozzle plate 81 Inkjet recording apparatus (liquid ejection apparatus) )
M Inkjet head (liquid ejection head)

Claims (12)

A perovskite oxide represented by ABO ₃ having a single crystal structure or a uniaxially oriented crystal structure,
The main component of the A site is Pb , and the B site contains at least three elements selected from Zn, Mg, Nb, Sc, In, Yb, Ni, Ta, and Ti ,
It has a plurality of crystal phases selected from tetragonal, rhombohedral, orthorhombic, cubic, pseudocubic and monoclinic, and the plurality of crystal phases are <100> oriented. Perovskite oxide. (Pb _k , Α _l ) _x (Zn _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + l = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.2 <m <0.4, 0. 5 <n <0.7, 0.05 <o <0.2, 0 ≦ p <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any element of Pb, Sc, In, Yb, Ni, Ta, Co, W, Fe, Sn, or Mg.) The perovskite type according to claim 1 Oxide. (Pb _k , Α _l ) _x (Mg _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.3, 0. 3 <n <0.5, 0.2 <o <0.4, 0 ≦ p <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, or Sn.) The perovskite oxide according to claim 1 . (Pb _k , Α _l ) _x (Ni _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.3, 0. 3 <n <0.5, 0.3 <o <0.5, 0 ≦ p <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, or Sn.) The perovskite oxide according to claim 1 . (Pb _k , Α _l ) _x (Sc _m , Ta _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0. 1 <n <0.4, 0.3 <o <0.5, 0 ≦ p <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, or Sn.) The perovskite oxide according to claim 1 . (Pb _k , Α _l ) _x (Sc _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0. 1 <n <0.4, 0.3 <o <0.5, 0 ≦ p <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, or Sn.) The perovskite oxide according to claim . (Pb _k , Α _l ) _x (Yb _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + 1 = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.1 <m <0.4, 0. 1 <n <0.4, 0.4 <o <0.6, 0 ≦ p <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, or Sn.) The perovskite oxide according to claim 1 . (Pb _k , Α _l ) _x (In _m , Nb _n , Ti _o , Β _p ) _y O _Three
(Wherein 1 ≦ x / y <1.5, k + l = 1, 0.7 ≦ k ≦ 1, 0 ≦ l ≦ 0.3, m + n + o + p = 1, 0.2 <m <0.4, 0. 2 <n <0.4, 0.2 <o <0.5, 0 ≦ p <0.3, and α represents any element of La, Ca, Ba, Sr, Bi, or Sb , Β represents any one element of Pb, Sc, Yb, Ta, Mg, Ni, Co, W, Fe, or Sn.) The perovskite oxide according to claim 1 . The perovskite oxide according to any one of claims 1 to 8, wherein the perovskite oxide has a film thickness of 1 µm to 10 µm. 10. A piezoelectric element comprising: a piezoelectric layer containing the perovskite oxide according to claim 1; and a pair of electrodes in contact with the piezoelectric layer. 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 using the piezoelectric element according to claim 10 as the piezoelectric element. A liquid discharge apparatus comprising the liquid discharge head according to claim 11.