WO2024070625A1 - 無鉛圧電組成物、及び圧電素子 - Google Patents

無鉛圧電組成物、及び圧電素子 Download PDF

Info

Publication number
WO2024070625A1
WO2024070625A1 PCT/JP2023/033007 JP2023033007W WO2024070625A1 WO 2024070625 A1 WO2024070625 A1 WO 2024070625A1 JP 2023033007 W JP2023033007 W JP 2023033007W WO 2024070625 A1 WO2024070625 A1 WO 2024070625A1
Authority
WO
WIPO (PCT)
Prior art keywords
piezoelectric
subphase
lead
composition
main phase
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/033007
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
吉進 廣瀬
健太郎 市橋
正人 山崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Niterra Co Ltd
Original Assignee
Niterra Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Niterra Co Ltd filed Critical Niterra Co Ltd
Priority to JP2024520929A priority Critical patent/JP7676664B2/ja
Priority to CN202380055206.1A priority patent/CN119604477A/zh
Priority to KR1020257009355A priority patent/KR102949806B1/ko
Priority to EP23871861.3A priority patent/EP4596521A1/en
Priority to TW112137307A priority patent/TW202423878A/zh
Publication of WO2024070625A1 publication Critical patent/WO2024070625A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/495—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G33/00—Compounds of niobium
    • C01G33/006—Compounds containing niobium, with or without oxygen or hydrogen, and containing two or more other elements
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G45/00—Compounds of manganese
    • C01G45/20—Compounds containing manganese, with or without oxygen or hydrogen, and containing one or more other elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/01—Manufacture or treatment
    • H10N30/06—Forming electrodes or interconnections, e.g. leads or terminals
    • H10N30/067—Forming single-layered electrodes of multilayered piezoelectric or electrostrictive parts
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/50—Piezoelectric or electrostrictive devices having a stacked or multilayer structure
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/80—Constructional details
    • H10N30/85—Piezoelectric or electrostrictive active materials
    • H10N30/853—Ceramic compositions
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3215—Barium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3232—Titanium oxides or titanates, e.g. rutile or anatase
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3244—Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3251—Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/652—Reduction treatment
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/76—Crystal structural characteristics, e.g. symmetry
    • C04B2235/768—Perovskite structure ABO3
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/80—Phases present in the sintered or melt-cast ceramic products other than the main phase
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/638—Removal thereof

Definitions

  • the present invention relates to a lead-free piezoelectric composition and a piezoelectric element.
  • piezoelectric elements are made from PZT (lead zirconate titanate)-based materials.
  • PZT lead zirconate titanate
  • the lead contained in PZT is seen as a problem because it causes environmental burden, and in recent years, development of piezoelectric elements made from lead-free materials has progressed.
  • a lead-free piezoelectric composition has been proposed that has a main phase formed of a first crystal phase made of an alkali niobate-based perovskite-type oxide and a subphase containing a second crystal made of an M-Ti-O-based spinel compound (wherein the element M is a monovalent to tetravalent element) (see Patent Document 1).
  • the alkali niobate perovskite oxide that constitutes the main phase is a material that is inherently prone to the formation of voids that cause a deterioration in the piezoelectric properties, but the voids in the main phase are filled with a subphase that contains second crystals, stabilizing the structure of the main phase (first crystal phase). Therefore, the lead-free piezoelectric composition has excellent piezoelectric properties. In other words, when force is applied to the lead-free piezoelectric composition, a voltage is generated, and when voltage is applied, the lead-free piezoelectric composition expands and contracts in dimensions and changes in shape.
  • the above-mentioned lead-free piezoelectric composition has excellent piezoelectric properties, it has a low dielectric breakdown voltage and therefore has a problem with insulation properties.
  • the object of the present invention is to provide a lead-free piezoelectric composition that has excellent piezoelectric properties and excellent insulating properties.
  • a lead-free piezoelectric composition having a main phase containing an alkali niobate-based perovskite-type oxide and a subphase containing a Mn—Ti—O-based oxide, wherein the Mn—Ti—O-based oxide in the subphase has a maximum particle size of 35 ⁇ m or less and a number-based cumulative 80% particle size (D80) of 32 ⁇ m or less.
  • ⁇ 2> The lead-free piezoelectric composition according to ⁇ 1>, wherein the average particle size of the Mn-Ti-O oxide in the subphase is 24 ⁇ m or less.
  • ⁇ 3> The lead-free piezoelectric composition according to ⁇ 1> or ⁇ 2>, wherein the Mn-Ti-O-based oxide contains MnTi 2 O 4 or Mn 2 TiO 4 .
  • a piezoelectric element including a laminate of a piezoelectric ceramic layer formed from the lead-free piezoelectric composition described in any one of ⁇ 1> to ⁇ 3> 2 and an electrode attached to the piezoelectric ceramic layer.
  • 1 is a perspective view of a piezoelectric element according to a first embodiment; 1 is a cross-sectional view of a piezoelectric element according to a second embodiment.
  • the lead-free piezoelectric composition and piezoelectric element according to the embodiment will be described below.
  • the lead-free piezoelectric composition has a main phase containing an alkali niobate-based perovskite-type oxide and a subphase containing an Mn-Ti-O-based oxide.
  • the main phase is formed of a first crystal phase made of an alkali niobate perovskite oxide.
  • the alkali niobate perovskite oxide is represented by the following composition formula (1).
  • Element A1 is at least one of the alkali metals Li, Na, and K.
  • Element M1 is at least one of the alkaline earth metals Ba (barium), Ca (calcium), and Sr (strontium).
  • element A1 and element M1 are arranged in the A site of the perovskite structure, and Nb (niobium), Mn (manganese), Ti (titanium) and Zr (zirconium) are arranged in the B site.
  • values that are preferable in terms of the electrical properties or piezoelectric properties (particularly the piezoelectric constant d 33 ) of the lead-free piezoelectric composition are selected from among values that establish a perovskite structure.
  • the coefficient c for the entire A site satisfies 0.80 ⁇ c ⁇ 1.10, preferably 0.84 ⁇ c ⁇ 1.08, and more preferably 0.88 ⁇ c ⁇ 1.07.
  • d1 0 (composition not containing Nb)
  • d2 0 (composition not containing Mn)
  • the coefficient d4 of Zr may be zero (i.e., the composition may not contain Zr).
  • the coefficient e is a positive or negative value indicating an oxygen deficiency or excess, with the oxygen coefficient usually being 3.
  • the oxygen coefficient 3+e can take a value where the main phase constitutes a perovskite-type oxide.
  • the value of the coefficient e can be calculated from the electrical neutrality condition of the main phase composition. However, a composition that deviates slightly from the electrical neutrality condition is also acceptable for the main phase composition.
  • oxides whose main metal components are K, Na, and Nb are called "KNN” or “KNN material” and have excellent piezoelectric and electrical properties.
  • the coefficient a1 of K is 0 ⁇ a1 ⁇ 0.6
  • the coefficient a2 of Na is 0 ⁇ a1 ⁇ 0.6
  • the coefficient a3 of Li is 0 ⁇ a3 ⁇ 0.2 (preferably, 0 ⁇ a3 ⁇ 0.1).
  • the subphase is formed of a second crystal phase containing Mn-Ti-O oxides.
  • Mn-Ti-O oxides are oxides containing Mn (manganese) and Ti (titanium), and are represented, for example, by the following composition formula (2):
  • the coefficient y satisfies 2 ⁇ y ⁇ 8.
  • the Mn-Ti-O based oxide may be MnTi 2 O 4 .
  • the Mn-Ti-O based oxide may be Mn 2 TiO 4 .
  • the composition of Mn and Ti in the Mn-Ti-O based oxide may deviate from the desired value within a range of ⁇ 0.2.
  • the lead-free piezoelectric composition of this embodiment may contain other crystal phases (such as a third crystal phase) besides the second crystal phase, as long as this does not impair the objective of the present invention.
  • the maximum particle size of the Mn-Ti-O oxide in the subphase is 35 ⁇ m or less. The method for measuring the maximum particle size of the Mn-Ti-O oxide will be described later.
  • the number-based cumulative 80% particle size (D80) of the Mn-Ti-O oxide in the subphase is 32 ⁇ m or less.
  • the method for measuring the number-based cumulative 80% particle size (D80) will be described later.
  • a lead-free piezoelectric composition that has excellent piezoelectric properties and excellent insulating properties (i.e., a high dielectric breakdown voltage) can be obtained.
  • the average particle size of the Mn-Ti-O oxide in the subphase is 24 ⁇ m or less. The method for measuring the average particle size of the Mn-Ti-O oxide will be described later.
  • the average particle size of the Mn-Ti-O oxide in the subphase is within the above range, it is easy to improve the piezoelectric properties and insulating properties of the lead-free piezoelectric composition.
  • the subphase which includes the second crystal phase that satisfies the above-mentioned conditions, is arranged in a scattered manner within the main phase consisting of the first crystal phase.
  • the subphase fills the voids (gaps) formed between the fine crystals of the main phase.
  • the subphase does not have piezoelectric properties, its presence in the main phase improves the sinterability and structural stability of the lead-free piezoelectric composition, as well as improving its insulating properties.
  • the proportion of the subphase contained in the lead-free piezoelectric composition is not particularly limited as long as it does not impair the object of the present invention, but it is preferable that it is, for example, 0.5 volume % or more and 5 volume % or less.
  • FIG. 1 is a perspective view of the piezoelectric element 200 according to the first embodiment.
  • the piezoelectric element 200 according to this embodiment has a disk-shaped appearance and includes a disk-shaped piezoelectric layer (an example of a piezoelectric ceramic layer) 100 and electrodes 301, 302 attached to the upper and lower surfaces of the piezoelectric layer 100.
  • the piezoelectric layer 100 is formed from the lead-free piezoelectric composition described above.
  • the piezoelectric layer 100 is polarized in the thickness direction.
  • the electrodes 301, 302 are made of, for example, Au.
  • the piezoelectric element 200 According to the first embodiment, multiple types of raw material powders necessary for forming the main phase are prepared, and these raw material powders are weighed out to obtain the desired composition.
  • the raw material powders may be oxides, carbonates, hydroxides, etc. of the elements contained in the main phase.
  • Ethanol is added to the mixture of the weighed raw material powders, and the mixture is wet-mixed using a ball mill, preferably for 15 hours or more, to obtain a slurry.
  • the obtained slurry is dried, and the mixed powder obtained after drying is calcined, for example, in an air atmosphere at a temperature condition of 600 to 1000°C for 1 to 10 hours, to obtain a powdered calcined product of the main phase.
  • raw material powders necessary for forming the subphase are prepared, and these raw material powders are weighed out to obtain the desired composition.
  • the raw material powders may be oxides, carbonates, hydroxides, etc. of the elements contained in the subphase.
  • Ethanol is added to the mixture of the weighed raw material powders, and the mixture is wet-mixed using a ball mill, preferably for 15 hours or more, to obtain a slurry.
  • the obtained slurry is dried, and the mixed powder obtained after drying is calcined, for example, in an air atmosphere at a temperature condition of 600 to 1000°C for 1 to 10 hours to obtain a powdered calcined product of the subphase.
  • a dispersant, binder, and ethanol are added to the obtained calcined main phase and calcined subphase products, and the mixture is crushed and mixed to obtain a slurry.
  • the obtained slurry is then dried, and the obtained dried product is appropriately granulated and uniaxially pressed under a pressure condition of, for example, 20 MPa to obtain a disk-shaped pre-formed body.
  • the pre-formed body is then subjected to a CIP process (cold isostatic pressing process) under a pressure condition of, for example, 150 MPa to obtain a molded body.
  • the obtained molded body is subjected to a binder removal process by, for example, holding it at a temperature of 200 to 400°C for 2 to 10 hours.
  • the molded body after the binder removal process is then fired for 2 to 5 hours at a temperature of, for example, 1000 to 1200°C in a reducing atmosphere where the pressure is controlled so that it is at least one order of magnitude more reducing than the equilibrium oxygen partial pressure of Ni/NO, to obtain a piezoelectric layer.
  • Electrodes made of Au are formed on both the front and back surfaces of the obtained piezoelectric layer, for example by sputtering. After that, the laminate with the electrodes formed on the piezoelectric layer is subjected to a polarization process in which a DC voltage of 5 kV/mm is applied in silicone oil at 50°C, thereby expressing the voltage characteristics of the piezoelectric layer. In this way, the piezoelectric element 200 is obtained.
  • the subphase is formed of a second crystal phase containing Mn-Ti-O oxides, as described above.
  • the size of the crystal grains in this subphase can be controlled to a desired size by appropriately setting the grain size of the subphase calcined product and the firing temperature of the molded body after the binder removal treatment performed in a reducing atmosphere.
  • the larger the grain size of the subphase calcined product the larger the crystal grains of the subphase of the final lead-free piezoelectric composition will be.
  • the higher the firing temperature of the molded body after the binder removal treatment performed in a reducing atmosphere the larger the crystal grains of the subphase of the final lead-free piezoelectric composition will be.
  • FIG. 2 is a cross-sectional view of the piezoelectric element 10 according to the second embodiment.
  • the piezoelectric element 10 according to the present embodiment includes a piezoelectric layer (an example of a piezoelectric ceramic layer) 11, a plurality of internal electrodes 12, 13 in contact with the piezoelectric layer 11, and two external electrodes 14, 15 connected to the internal electrodes 12, 13.
  • the piezoelectric layer 11 is formed from the above-mentioned lead-free piezoelectric composition.
  • the internal electrodes 12, 13 are mainly composed of a base metal (e.g., nickel).
  • the piezoelectric layer 11 and the internal electrodes 12, 13 are alternately laminated.
  • the piezoelectric layer 11 and the internal electrodes 12, 13 are laminated in the order of the piezoelectric layer 11, the internal electrode 12, the piezoelectric layer 11, the internal electrode 13, the piezoelectric layer 11, etc., and one piezoelectric layer 11 is sandwiched between the two internal electrodes 12, 13.
  • the two external electrodes 14, 15 are disposed on the outer surface of the laminate of the piezoelectric layer 11 and the internal electrodes 12, 13.
  • the external electrodes 14, 15 are mainly composed of Au, for example.
  • One end of one of the two internal electrodes 12, 13 in contact with one piezoelectric layer 11 is connected to one external electrode 14, and one end of the other internal electrode 13 is connected to the other external electrode 15.
  • the piezoelectric element 10 According to the second embodiment, multiple types of raw material powders necessary for forming the main phase are prepared, and these raw material powders are weighed out to obtain the desired composition.
  • the raw material powders may be oxides, carbonates, hydroxides, etc. of the elements contained in the main phase.
  • Ethanol is added to the mixture of the weighed raw material powders, and the mixture is wet-mixed using a ball mill, preferably for 15 hours or more, to obtain a slurry.
  • the obtained slurry is dried, and the mixed powder obtained after drying is calcined, for example, in an air atmosphere at a temperature condition of 600 to 1000°C for 1 to 10 hours to obtain a powdered calcined product of the main phase.
  • raw material powders necessary for forming the subphase are prepared, and these raw material powders are weighed out to obtain the desired composition.
  • the raw material powders may be oxides, carbonates, hydroxides, etc. of the elements contained in the subphase.
  • Ethanol is added to the mixture of the weighed raw material powders, and the mixture is wet-mixed using a ball mill, preferably for 15 hours or more, to obtain a slurry.
  • the obtained slurry is dried, and the mixed powder obtained after drying is calcined, for example, in an air atmosphere at a temperature condition of 600 to 1000°C for 1 to 10 hours to obtain a powdered calcined product of the subphase.
  • a dispersant, binder, and organic solvent e.g., toluene
  • a dispersant, binder, and organic solvent e.g., toluene
  • the mixture is pulverized and mixed to obtain a slurry.
  • the slurry is processed into a sheet shape using a doctor blade method or the like to produce a ceramic green sheet.
  • an electrode layer that will become the internal electrode is formed on one side of the ceramic green sheet by, for example, screen printing using a conductive paste for the internal electrode.
  • the electrode layer is mainly composed of a base metal, for example nickel (Ni).
  • the laminate after the binder removal process is fired for 2 to 5 hours under temperature conditions of, for example, 1000 to 1200°C and in a reducing atmosphere in which the pressure is controlled to be at least one order of magnitude more reducing than the equilibrium oxygen partial pressure of Ni/NO.
  • a pair of external electrodes made of Au are formed on the sides of the laminate, for example by sputtering.
  • the pair of external electrodes are formed facing each other with the laminate between them.
  • a polarization process is performed on the laminate with the external electrodes formed, thereby obtaining a piezoelectric element 10.
  • the subphase is formed of a second crystal phase containing Mn-Ti-O oxides, as described above.
  • the size of the crystal grains in this subphase can be controlled to a desired size by appropriately setting the grain size of the subphase calcined product and the firing temperature of the molded body after the binder removal treatment performed in a reducing atmosphere.
  • the larger the grain size of the subphase calcined product the larger the crystal grains of the subphase of the final lead-free piezoelectric composition will be.
  • the higher the firing temperature of the molded body after the binder removal treatment performed in a reducing atmosphere the larger the crystal grains of the subphase of the final lead-free piezoelectric composition will be.
  • the manufacturing methods of the above-mentioned embodiment 1 and embodiment 2 are both examples, and various other steps and processing conditions for manufacturing a piezoelectric element can be adopted.
  • the raw materials instead of separately producing the main phase and subphase calcined products and then mixing and firing the powders of both, the raw materials may be mixed in a ratio according to the final composition of the lead-free piezoelectric composition, and the mixture may be fired.
  • the method of separately producing the main phase and subphase calcined products and then mixing them it is easier to control the composition of the main phase and subphase more strictly, so it is possible to increase the yield of the lead-free piezoelectric composition.
  • metals or alloys such as platinum (Pt), silver-palladium (Ag-Pd), and silver (Ag) may be used as the material for the electrodes.
  • the lead-free piezoelectric composition and piezoelectric element disclosed in this specification have excellent piezoelectric characteristics, a high dielectric breakdown voltage, and excellent insulating properties.
  • Such lead-free piezoelectric compositions and piezoelectric elements can be widely used for vibration detection, pressure detection, oscillation, piezoelectric device applications, etc.
  • they can be used in sensors that detect various vibrations (Knox sensors and combustion pressure sensors, etc.), piezoelectric devices such as vibrators, actuators, and filters, high-voltage generators, micro power sources, various driving devices, position control devices, vibration suppression devices, fluid ejection devices (paint ejection, fuel ejection, etc.), etc.
  • the obtained molded body was subjected to a binder removal process by holding it at a temperature of 200 to 400°C for 2 to 10 hours.
  • the molded body after the binder removal process was then held and fired for 2 to 5 hours at a temperature of 1000 to 1200°C in a reducing atmosphere where the pressure was controlled to be at least one order of magnitude lower than the equilibrium oxygen partial pressure of Ni/NO, to obtain a piezoelectric layer.
  • Electrodes made of Au were formed on both the front and back surfaces of the obtained piezoelectric layer by sputtering. After that, the laminate with the electrodes formed on the piezoelectric layer was subjected to a polarization process in which a direct current voltage of 5 kV/mm was applied in silicone oil at 50°C to express the voltage characteristics of the piezoelectric layer, and the piezoelectric element of each example was obtained.
  • Example 1 the particle size of the subphase calcined product and the firing temperature of the molded body after the binder removal process in a reducing atmosphere were appropriately adjusted so as to be different from each other.
  • Comparative Example 1 The piezoelectric element of Comparative Example 1 was produced in the same manner as in Example 7, except that the particle size of the subphase calcined product was set to be larger than that of Example 7, and the firing temperature of the molded body after the binder removal treatment performed in a reducing atmosphere was set to be higher than that of Example 7.
  • Comparative Example 2 A main phase calcined product was prepared similarly to Example 1.
  • the subphase calcined product was produced by the following method. Li2CO3 powder and TiO2 powder were prepared as raw material powders, and the subphase calcined product was produced similarly to Example 1, etc., except that each of these raw material powders was weighed to have the composition ( LiTi2O4 ) shown in Table 3. Using these main phase calcined products and subphase calcined products, a piezoelectric element of Comparative Example 2 was produced similarly to Example 1, etc.
  • Comparative Example 3 A main phase calcined product was prepared similarly to Example 1.
  • the subphase calcined product was produced by the following method. As raw material powders, Li2CO3 powder, Fe2O3 powder, MgO powder, and TiO2 powder were prepared, and the subphase calcined product was produced similarly to Example 1, etc., except that each of these raw material powders was weighed to have the composition ( LiFeMgTiO4 ) shown in Table 3. Using these main phase calcined products and subphase calcined products, a piezoelectric element of Comparative Example 3 was produced similarly to Example 1, etc.
  • piezoelectric constant d 33 The piezoelectric constant (pC/N) was measured using a d33 meter (product name "ZJ-4B", manufactured by the Institute of Vocal Music, Chinese Academy of Sciences) for each of the piezoelectric elements (piezoelectric layers) of Example 3, Comparative Example 2, and Comparative Example 3. The results are shown in Table 3.
  • the dielectric breakdown voltage (kV/mm) was measured by the method shown below. In the state where the voltage element is put in the silicone oil at 25°C, a DC voltage was applied for 1 minute under the condition of 1 kV/mm, and then, the DC voltage was applied for 1 minute each under the condition that the applied voltage was increased by 1 kV/mm. Then, the applied voltage (kV/mm) when the voltage element was broken down was taken as the dielectric breakdown voltage (dielectric breakdown electric field) of the voltage element. The results are shown in Tables 2 and 3.
  • composition of the compounds contained in the subphases was identified using powder X-ray diffraction (XRD) for the polished surfaces of each example and comparative example.
  • XRD powder X-ray diffraction
  • the average value of the major axis diameter and the minor axis diameter was set to the grain size (particle size) of each crystal grain.
  • the average value of the grain size of each crystal grain within the measurement range thus determined was set to the average grain size ( ⁇ m) of the subphase crystal grains.
  • the magnification for taking SEM images was first 1000x. Then, when the crystal particles could not be identified from the obtained SEM images, the magnification was changed to 10000x. As a result, only Example 1 had SEM images taken at a magnification of 10000x, and in the other cases, SEM images were taken at a magnification of 1000x.
  • the lead - free piezoelectric compositions used in the piezoelectric elements of Examples 1 to 7 have a subphase made of MnTi2O4 (Mn-Ti-O oxide).
  • Mn-Ti-O oxide MnTi2O4
  • the maximum grain size of the crystal grains in the subphase is 35 ⁇ m or less
  • the cumulative 80% grain size (D80) based on the number is 32 ⁇ m or less. It was confirmed that Examples 1 to 7 have excellent insulation properties, with a dielectric breakdown voltage of 16 kV/mm or more.
  • Example 3 the results of the measurement of the piezoelectric constant of Example 3, which was carried out as a representative example, confirmed that the lead-free piezoelectric composition used in the piezoelectric elements of Example 3 and the like has excellent piezoelectric properties.
  • Comparative Example 1 has a subphase made of MnTiO (Mn-Ti-O oxide), but the maximum grain size (29 ⁇ m) and the cumulative 80% grain size (D80) (37 ⁇ m) of the crystal grains in the subphase are both too large.
  • the dielectric breakdown voltage was 13 kV/mm, and it was confirmed that the insulating properties were low.
  • Comparative Example 2 is a case in which the subphase is a compound ( LiTi2O4 ) that contains Ti ( titanium ) but does not contain Mn (manganese). Although Comparative Example 2 has excellent piezoelectric properties like Example 3, the dielectric breakdown voltage was 10 kV/mm, and it was confirmed that the dielectric properties were low.
  • Comparative Example 3 is a case in which a compound (LiFeMgTiO 4 ) containing Ti (titanium) but not Mn (manganese) is provided as a subphase. Comparative Example 3 has excellent piezoelectric properties like Example 3, but the dielectric breakdown voltage was 12 kV/mm, and it was confirmed that the insulating properties were low.
  • Example 8 to 10 The main phase calcined product was prepared in the same manner as in Example 1.
  • the subphase calcined product was produced by the following method. As raw material powders, MnCO 3 powder and TiO 2 powder were prepared, and each of these raw material powders was weighed to have the composition (Mn 2 TiO 4 ) shown in Table 2. An appropriate amount of ethanol was added to the mixture of each weighed raw material powder, and the mixture was wet-mixed using a ball mill for 15 hours to obtain a slurry. The obtained slurry was dried, and the mixed powder obtained after drying was calcined in an air atmosphere at a temperature condition of 600 to 1100 ° C. for 1 to 10 hours to obtain a subphase calcined product. Using these main phase calcined products and subphase calcined products, the piezoelectric elements of Examples 8 to 10 were produced in the same manner as in Example 1, etc.
  • the main phase was analyzed, the subphase was analyzed, the dielectric breakdown voltage (kV/mm) was measured, and the grain size (maximum grain size, average grain size, D80) of the subphase crystal grains was measured using the same methods as in Example 1, etc.
  • the results are shown in Table 4.
  • the lead-free piezoelectric compositions used in the piezoelectric elements of Examples 8 to 10 have a subphase consisting of Mn 2 TiO 4 (Mn-Ti-O oxide).
  • Mn-Ti-O oxide Mn 2 TiO 4
  • the maximum grain size of the crystal grains in the subphase is 35 ⁇ m or less
  • the cumulative 80% grain size (D80) based on the number is 32 ⁇ m or less. It was confirmed that Examples 8 to 10 have a dielectric breakdown voltage of 16 kV/mm or more, and have excellent insulating properties.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Compositions Of Oxide Ceramics (AREA)
PCT/JP2023/033007 2022-09-30 2023-09-11 無鉛圧電組成物、及び圧電素子 Ceased WO2024070625A1 (ja)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP2024520929A JP7676664B2 (ja) 2022-09-30 2023-09-11 無鉛圧電組成物、及び圧電素子
CN202380055206.1A CN119604477A (zh) 2022-09-30 2023-09-11 无铅压电组合物和压电元件
KR1020257009355A KR102949806B1 (ko) 2022-09-30 2023-09-11 무연 압전 조성물 및 압전 소자
EP23871861.3A EP4596521A1 (en) 2022-09-30 2023-09-11 Lead-free piezoelectric composition and piezoelectric element
TW112137307A TW202423878A (zh) 2022-09-30 2023-09-28 無鉛壓電組成物、及壓電元件

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-158308 2022-09-30
JP2022158308 2022-09-30

Publications (1)

Publication Number Publication Date
WO2024070625A1 true WO2024070625A1 (ja) 2024-04-04

Family

ID=90477439

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/033007 Ceased WO2024070625A1 (ja) 2022-09-30 2023-09-11 無鉛圧電組成物、及び圧電素子

Country Status (6)

Country Link
EP (1) EP4596521A1 (https=)
JP (1) JP7676664B2 (https=)
KR (1) KR102949806B1 (https=)
CN (1) CN119604477A (https=)
TW (1) TW202423878A (https=)
WO (1) WO2024070625A1 (https=)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025047298A1 (ja) * 2023-08-31 2025-03-06 日本特殊陶業株式会社 無鉛圧電組成物、圧電素子、および装置
WO2025126556A1 (ja) * 2023-12-11 2025-06-19 日本特殊陶業株式会社 無鉛圧電組成物、圧電素子、および装置

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002137966A (ja) * 2000-10-31 2002-05-14 Kyocera Corp 圧電磁器および圧電素子
JP2005179144A (ja) * 2003-12-22 2005-07-07 Tdk Corp 圧電磁器およびその製造方法
JP2014177355A (ja) * 2013-03-13 2014-09-25 Taiyo Yuden Co Ltd 圧電セラミックス、圧電素子、及び圧電セラミックスの製造方法
WO2014156015A1 (ja) * 2013-03-29 2014-10-02 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、装置、及び、無鉛圧電磁器組成物の製造方法
JP2019031424A (ja) * 2017-08-09 2019-02-28 日本特殊陶業株式会社 無鉛圧電磁器組成物、圧電素子および圧電素子利用装置
JP2019048749A (ja) * 2017-09-12 2019-03-28 日本特殊陶業株式会社 無鉛圧電磁器組成物、及び圧電素子
WO2022215666A1 (ja) * 2021-04-08 2022-10-13 日本特殊陶業株式会社 無鉛圧電磁器組成物及び圧電素子
JP2023032022A (ja) * 2021-08-26 2023-03-09 日本特殊陶業株式会社 圧電素子

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101857436B (zh) 2010-06-12 2013-03-13 中国地质大学（武汉） 一类铌酸钾钠基无铅压电陶瓷粉体的制备方法
JP6327914B2 (ja) 2014-04-11 2018-05-23 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、及び、無鉛圧電磁器組成物の製造方法
JP5823014B2 (ja) 2014-04-11 2015-11-25 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、及び、無鉛圧電磁器組成物の製造方法
JP2015205805A (ja) 2014-04-11 2015-11-19 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、及び、無鉛圧電磁器組成物の製造方法
JP2018088524A (ja) 2016-11-22 2018-06-07 日本特殊陶業株式会社 無鉛圧電磁器組成物及び圧電素子

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002137966A (ja) * 2000-10-31 2002-05-14 Kyocera Corp 圧電磁器および圧電素子
JP2005179144A (ja) * 2003-12-22 2005-07-07 Tdk Corp 圧電磁器およびその製造方法
JP2014177355A (ja) * 2013-03-13 2014-09-25 Taiyo Yuden Co Ltd 圧電セラミックス、圧電素子、及び圧電セラミックスの製造方法
WO2014156015A1 (ja) * 2013-03-29 2014-10-02 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、装置、及び、無鉛圧電磁器組成物の製造方法
JP5715309B2 (ja) 2013-03-29 2015-05-07 日本特殊陶業株式会社 無鉛圧電磁器組成物、それを用いた圧電素子、装置、及び、無鉛圧電磁器組成物の製造方法
JP2019031424A (ja) * 2017-08-09 2019-02-28 日本特殊陶業株式会社 無鉛圧電磁器組成物、圧電素子および圧電素子利用装置
JP2019048749A (ja) * 2017-09-12 2019-03-28 日本特殊陶業株式会社 無鉛圧電磁器組成物、及び圧電素子
WO2022215666A1 (ja) * 2021-04-08 2022-10-13 日本特殊陶業株式会社 無鉛圧電磁器組成物及び圧電素子
JP2023032022A (ja) * 2021-08-26 2023-03-09 日本特殊陶業株式会社 圧電素子

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025047298A1 (ja) * 2023-08-31 2025-03-06 日本特殊陶業株式会社 無鉛圧電組成物、圧電素子、および装置
WO2025126556A1 (ja) * 2023-12-11 2025-06-19 日本特殊陶業株式会社 無鉛圧電組成物、圧電素子、および装置

Also Published As

Publication number Publication date
TW202423878A (zh) 2024-06-16
KR20250053162A (ko) 2025-04-21
CN119604477A (zh) 2025-03-11
JPWO2024070625A1 (https=) 2024-04-04
KR102949806B1 (ko) 2026-04-09
JP7676664B2 (ja) 2025-05-14
EP4596521A1 (en) 2025-08-06

Similar Documents

Publication Publication Date Title
JP5337513B2 (ja) 圧電／電歪磁器組成物
JP7791315B2 (ja) 無鉛圧電組成物、及び圧電素子
JPWO2010128647A1 (ja) 圧電セラミックスおよびその製造方法ならびに圧電デバイス
JP5929640B2 (ja) 圧電磁器および圧電素子
JP7676664B2 (ja) 無鉛圧電組成物、及び圧電素子
TWI852146B (zh) 壓電元件、及壓電元件之製造方法
JP6175528B2 (ja) 圧電デバイス
JP5597368B2 (ja) 積層型電子部品およびその製法
JP7707434B2 (ja) 無鉛圧電組成物、及び圧電素子
JP7534553B2 (ja) 無鉛圧電磁器組成物、および圧電素子
JP5894222B2 (ja) 積層型電子部品およびその製法
JP2025021632A (ja) 無鉛圧電組成物、及び圧電素子
JP2025152811A (ja) 圧電セラミック積層体
TW202543483A (zh) 積層壓電陶瓷元件及裝置
TW202602819A (zh) 積層壓電陶瓷元件及裝置
JPH09202661A (ja) 圧電磁器組成物

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2024520929

Country of ref document: JP

Kind code of ref document: A

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23871861

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 202517004051

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 202380055206.1

Country of ref document: CN

WWE Wipo information: entry into national phase

Ref document number: 2501001159

Country of ref document: TH

WWP Wipo information: published in national office

Ref document number: 202380055206.1

Country of ref document: CN

ENP Entry into the national phase

Ref document number: 20257009355

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1020257009355

Country of ref document: KR

WWP Wipo information: published in national office

Ref document number: 202517004051

Country of ref document: IN

WWP Wipo information: published in national office

Ref document number: 1020257009355

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 2023871861

Country of ref document: EP

Ref document number: 11202501047T

Country of ref document: SG

WWP Wipo information: published in national office

Ref document number: 11202501047T

Country of ref document: SG

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2023871861

Country of ref document: EP

Effective date: 20250430

WWP Wipo information: published in national office

Ref document number: 2023871861

Country of ref document: EP