Ceramic material comprising a pseudo-cubic phase, a process for preparing and uses of the same

Patent metadata

Field	Value
Publication number	US-11078122-B2
Application number	US-201816483581-A
Country	US
Kind code	B2
Filing date	Feb 2, 2018
Priority date	Feb 3, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

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(Bi 0.5 Na 0.5 )TiO 3 -y(Bi 0.5 K 0.5 )TiO 3 -z 1 SrHfO 3 -z 2 SrZrO 3 , wherein x+y+Z 1 +Z 2 =1; y, (z 1 +z 2 )≠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(Bi 0.5 K 0.5 )TiO 3 -z 1 SrHfO 3 -z 2 SrZrO 3 , wherein y+z 1 ,+z 2 =1; y, (z 1 +z 2 )≠0.

First claim

The invention claimed is:

1. A ceramic material having a chemical formula (I):
x (Bi 0.5 Na 0.5 )TiO 3 - y (Bi 0.5 K 0.5 )TiO 3 - z 1 SrHfO 3 - z 2 SrZrO 3   (I):

wherein:
x+y+z 1 +z 2 =1;
y and (z 1 +z 2 ) 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.

2. The ceramic material of claim 1 , wherein both z 1 and z 2 are greater than zero.

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

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

5. The ceramic material of claim 1 , wherein 0.01≤(z 1 +z 2 )≤0.15.

6. The ceramic material of claim 1 , wherein:
0.40≤x≤0.50;
0.40≤y≤0.50; and
0.02≤(z 1 +z 2 )≤0.10.

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

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

9. The ceramic material of claim 7 , wherein 0.01≤(z 1 +z 2 )≤0.25.

10. The ceramic material of claim 1 , wherein the ceramic material has a remnant polarization of less than 5 μC/cm 2 .

11. The ceramic material of claim 1 , wherein the ceramic material has an effective piezoelectric strain coefficient d 33 * of from 50 to 500 pm/V.

12. 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.

13. The ceramic material of claim 1 , wherein the ceramic material has a field induced polarization of from 10 to 50 μC/cm 2 .

14. 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.

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

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(Bi 0.5 Na 0.5 )Ti 3 -y(Bi 0.5 K 0.5 )TiO 3 -z 1 SrHfO 3 -z 2 SrZrO 3 ; 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 (Bi 0.5 Na 0.5 )TiO 3 precursors to (Bi 0.5 K 0.5 )TiO 3 precursors required to form a tetragonal phase; and
the molar ratio of at least one of SrHfO 3 precursors or SrZrO 3 precursors to (Bi 0.5 Na 0.5 )TiO 3 and (Bi 0.5 K 0.5 )TiO 3 precursors required to form the ceramic material which comprises a major proportion of the pseudo-cubic phase.

17. The method according to claim 16 , wherein a binary (Bi 0.5 Na 0.5 )TiO 3 —(Bi 0.5 K 0.5 )TiO 3 composition comprises a tetragonal phase having an axial ratio c/a of between 1.01 and 1.02.

18. The method according to claim 16 wherein x=0.

19. An actuator for a droplet deposition apparatus comprising:
a ceramic material having a chemical formula of x(Bi 0.5 Na 0.5 )TiO 3 -v(Bi 0.5 K 0.5 )TiO 3 -z 1 SrHfO 3 -z 2 SrZrO 3 ;
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+z 1 +z 2 =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.

Assignees

• Cann David
• Gibbons Brady
• Mardilovich Peter
• Xaar Technology Ltd

Inventors

• Cann David
• Gibbons Brady
• Mardilovich Peter

Classifications

• B41J2/14233

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• C04B2235/3298

  Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate · CPC title

• C04B35/6342

  Polyvinylacetals, e.g. polyvinylbutyral [PVB] · CPC title

• C04B2235/3201

  Alkali metal oxides or oxide-forming salts thereof · CPC title

• C04B35/6261

  Milling · CPC title