# US 11,078,122 B2 · Ceramic material comprising a pseudo-cubic phase, a process for preparing and uses of the same

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- Number: US 11,078,122 B2
- Document ID: US11078122B2
- Status: Granted
- Kind: B2
- Application number: 16/483,581
- Filed: 2018-02-02
- Published: 2020-01-09
- Granted: 2021-08-03
- Earliest claimed: 2017-02-03
- Assignees: Xaar Technology Limited
- Applicants: David Cann; Brady Gibbons; Peter Mardilovich
- Inventors: David Cann; Brady Gibbons; Peter Mardilovich
- Web page: https://patentgrep.com/patent/US11078122B2

## CPC

- C04B 35/4682: {based on BaTiO3 perovskite phase}
- C04B 35/49: containing also titanium oxides or titanates
- B41J 2/14201: {Structure of print heads with piezoelectric elements}
- B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm}
- C01G 29/006: {Compounds containing bismuth, with or without oxygen or hydrogen, and containing two or more other elements}
- C04B 35/46: based on titanium oxides or titanates (containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49)
- C04B 35/475: based on bismuth titanates
- C04B 35/6261: {Milling}
- C04B 35/6263: {characterised by their solids loadings, i.e. the percentage of solids}
- C04B 35/62645: {Thermal treatment of powders or mixtures thereof other than sintering}
- C04B 35/6342: {Polyvinylacetals, e.g. polyvinylbutyral [PVB]}
- C04B 35/64: Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F})
- H10N 30/097: by sintering
- H10N 30/2047: {Membrane type}
- H10N 30/802: {Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits}
- H10N 30/8536: {Alkaline earth metal based oxides, e.g. barium titanates}
- H10N 30/8542: {Alkali metal based oxides, e.g. lithium, sodium or potassium niobates}
- H10N 30/8561: {Bismuth-based oxides}
- B41J 2202/03: Specific materials used
- C01P 2002/34: perovskite-type (ABO3)
- C01P 2002/50: Solid solutions
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2006/40: Electric properties
- C04B 2235/32: Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B 2235/3201: Alkali metal oxides or oxide-forming salts thereof
- C04B 2235/3213: Strontium oxides or oxide-forming salts thereof
- C04B 2235/3237: Substoichiometric titanium oxides, e.g. Ti2O3
- C04B 2235/3244: Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
- C04B 2235/3248: Zirconates or hafnates, e.g. zircon
- C04B 2235/3249: containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT)
- C04B 2235/3298: Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
- C04B 2235/604: Pressing at temperatures other than sintering temperatures
- C04B 2235/6562: Heating rate
- C04B 2235/76: Crystal structural characteristics, e.g. symmetry
- C04B 2235/761: Unit-cell parameters, e.g. lattice constants
- C04B 2235/762: Cubic symmetry, e.g. beta-SiC
- C04B 2235/765: Tetragonal symmetry
- C04B 2235/768: Perovskite structure ABO3
- C04B 2235/788: Aspect ratio of the grains
- C04B 2235/79: Non-stoichiometric products, e.g. perovskites (ABO3) with an A/B-ratio other than 1
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

The present invention relates to a bismuth-based solid solution ceramic material, as well as a process for preparing the ceramic material and uses thereof, particularly in an actuator component employed, for example, in a droplet deposition apparatus. In particular, the present invention relates to a ceramic material having a general chemical formula (I): (I): x(Bi0.5Na0.5)TiO3-y(Bi0.5K0.5)TiO3-z1SrHfO3-z2SrZrO3, wherein x+y+Z1+Z2=1; y, (z1+z2)≠0; x≥0. In embodiments, the present invention also relates to a ceramic material having a general chemical formula (II): x(Bi0.5Na0.5)TiO3-y(Bi0.5K0.5)TiO3-y(Bi0.5K0.5)TiO3-ZiSrHfO3-z2SrZrO3, wherein x+y+z−i+z2=1; x, y, fa+z2)≠0; as well as a ceramic material of general formula (III): y(Bi0.5K0.5)TiO3-z1SrHfO3-z2SrZrO3, wherein y+z1,+z2=1; y, (z1+z2)≠0.

## Claims

### Claim 1

A ceramic material having a chemical formula (I):
x(Bi0.5Na0.5)TiO3-y(Bi0.5K0.5)TiO3-z1SrHfO3-z2SrZrO3 (I):
wherein:
x+y+z1+z2=1;
y and (z1+z2) are greater than zero;
x≥0; and
the ceramic material comprises at least 70 vol. % of a pseudo-cubic phase having at least one of an axial ratio c/a of from 0.995 to 1.005 or a rhombohedral angle of 90±0.5 degrees and wherein the ceramic material is capable of undergoing a field induced reversible transition from the pseudo-cubic phase to a tetragonal phase having an axial ratio c/a of between 1.005 and 1.02.

### Claim 2 (depends on 1)

The ceramic material of claim 1, wherein both z1 and z2 are greater than zero.

### Claim 3 (depends on 1)

The ceramic material of claim 1, wherein 0.25≤x≤0.65.

### Claim 4 (depends on 1)

The ceramic material of claim 1, wherein 0.25≤y≤0.75.

### Claim 5 (depends on 1)

The ceramic material of claim 1, wherein 0.01≤(z1+z2)≤0.15.

### Claim 6 (depends on 1)

The ceramic material of claim 1, wherein:
0.40≤x≤0.50;
0.40≤y≤0.50; and
0.02≤(z1+z2)≤0.10.

### Claim 7 (depends on 1)

The ceramic material of claim 1, wherein x=0.

### Claim 8 (depends on 7)

The ceramic material of claim 7, wherein 0.75≤y≤0.99.

### Claim 9 (depends on 7)

The ceramic material of claim 7, wherein 0.01≤(z1+z2)≤0.25.

### Claim 10 (depends on 1)

The ceramic material of claim 1, wherein the ceramic material has a remnant polarization of less than 5 μC/cm2.

### Claim 11 (depends on 1)

The ceramic material of claim 1, wherein the ceramic material has an effective piezoelectric strain coefficient d33* of from 50 to 500 pm/V.

### Claim 12 (depends on 1)

The ceramic material of claim 1, wherein the ceramic material has a maximum electromechanical strain value of from 0.1% to 0.5%, when measured at 10 Hz and at standard temperature and pressure.

### Claim 13 (depends on 1)

The ceramic material of claim 1, wherein the ceramic material has a field induced polarization of from 10 to 50 μC/cm2.

### Claim 14 (depends on 1)

The ceramic material of claim 1, wherein the ceramic material is configured to be reversibly converted into a ceramic material comprising at least 50 vol. % of a tetragonal phase, when applying an electric field to the ceramic material.

### Claim 15 (depends on 14)

The ceramic material according to claim 14, wherein the tetragonal phase has an axial ratio c/a of between 1.01 and 1.02.

### Claim 16

A method of preparing a ceramic material comprising:
mixing precursors of a ceramic material in predetermined molar ratios, the ceramic material having chemical formula of x(Bi0.5Na0.5)Ti3-y(Bi0.5K0.5)TiO3-z1SrHfO3-z2SrZrO3; and
utilizing the mixture of precursors in solid-state synthesis to prepare the ceramic material,
wherein:
x+y+z1+z2=1;
y and (z1+z2) are greater than zero;
x is greater than or equal to zero;
the ceramic material comprises at least 70 vol. % of a pseudo-cubic phase having at least one of an axial ratio c/a of from 0.995 to 1.005 or a rhombohedral angle of 90±0.5 degrees and wherein the ceramic material is capable of undergoing a field induced reversible transition from the pseudo-cubic phase to a tetragonal phase having an axial ratio c/a of between 1.005 and 1.02; and
the predetermined molar ratios of precursors are determined based on:
the molar ratio of (Bi0.5Na0.5)TiO3 precursors to (Bi0.5K0.5)TiO3 precursors required to form a tetragonal phase; and
the molar ratio of at least one of SrHfO3 precursors or SrZrO3 precursors to (Bi0.5Na0.5)TiO3 and (Bi0.5K0.5)TiO3 precursors required to form the ceramic material which comprises a major proportion of the pseudo-cubic phase.

### Claim 17 (depends on 16)

The method according to claim 16, wherein a binary (Bi0.5Na0.5)TiO3—(Bi0.5K0.5)TiO3 composition comprises a tetragonal phase having an axial ratio c/a of between 1.01 and 1.02.

### Claim 18 (depends on 16)

The method according to claim 16 wherein x=0.

### Claim 19

An actuator for a droplet deposition apparatus comprising:
a ceramic material having a chemical formula of x(Bi0.5Na0.5)TiO3-v(Bi0.5K0.5)TiO3-z1SrHfO3-z2SrZrO3;
an actuating element configured to cause an ejection of fluid from a chamber;
a first electrode adjacent to the ceramic material; and
a second electrode adjacent to the ceramic material
wherein:
x+y+z1+z2=1;
y and (z1+z2) are greater than zero;
x≥0;
the ceramic material comprises at least 70 vol. % of a pseudo-cubic phase having at least one of an axial ratio c/a of from 0.995 to 1.005 or a rhombohedral angle of 90±0.5 degrees and wherein the ceramic material is capable of undergoing a field induced reversible transition from the pseudo-cubic phase to a tetragonal phase having an axial ratio c/a of between 1.005 and 1.02; and
the first electrode and the second electrode are configured to apply an electric field to the ceramic material to cause the ejection.