IP Library Granted Patent US 9,738,990
Granted Patent B2
US 9,738,990 · App. 14/420,896 · Granted Aug 22, 2017

Method of liquid-phase epitaxial growth of lead zirconate titanate single crystals

Inventor: Vincent Fratello (Bellevue, WA)
Assignee: Quest Integrated, LLC
C30B19/12C30B19/02C30B19/04C30B29/32H01L41/18
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Quick Facts
Patent No.
US 9,738,990
App. No.
14/420,896
Granted
Aug 22, 2017
Kind
B2
Abstract

Growth of single crystals of lead zirconate titanate (PZT) and other perovskites is accomplished by liquid phase epitaxy onto a substrate of suitable structural and lattice parameter match. A solvent and specific growth conditions for stable growth are required to achieve the desired proportions of Zr and Ti.

Claims (25)

1. A method of growing a lead zirconate titanate (PZT) single crystal having room temperature PZT lattice parameters comprising

a=4.03±0.02 Å, c=4.15±0.02 Å, and b=a using liquid phase epitaxy, comprising:

providing a substrate in a solution, wherein the substrate has a perovskite crystal structure and one or more periodic repeat distances in the plane of growth that are integer multiples of the PZT periodic repeat distances of the same crystal orientation to within 2%, and wherein the solution comprises a solvent and a solute, and wherein the solute comprises PZT or PZT precursors PbO, TiO 2 , ZrO 2 , PbZrO 3 (PZ) and PbTiO 3 (PT); and

growing the PZT single crystal from the solution onto the substrate using liquid phase epitaxy, wherein the temperature of the solution is held to within 25° C. of a constant growth temperature, wherein the liquid phase epitaxy is performed at a temperature of greater than 700° C.

2. The method of claim 1 , wherein the solvent includes a compound selected from the group consisting of PbF 2 , LiF, NaF, KF, Na 3 AlF 6 , PbO, Pb 3 (PO 4 ) 2 , PbCl 2 , B 2 O 3 , WO 3 , MoO 3 , V 2 O 5 , P 2 O 5 , PbWO 4 , PbMoO 4 , Li 2 B 4 O 7 , Na 2 B 4 O 7 , K 2 B 4 O 7 , and Pb 2 V 2 O 7 .

3. The method of claim 1 , wherein the substrate has at least one room temperature substrate lattice parameter in the range 4.05±0.04 Å or a multiple of 4.05±0.04 Å by 2 or √2.

4. The method of claim 1 , wherein the solubilities of PT and PZ in the melt are equal.

5. The method of claim 1 , wherein the solubilities of titanium oxide and zirconium oxide in the melt are equal.

6. The method of claim 1 , wherein the PZT is Pb(Zr 0.52 Ti 0.48 )O 3 .

7. The method of claim 1 , wherein the substrate is selected from the group consisting of NdScO 3 , PrScO 3 , Sr(Na 1/4 Ta 3/4 )O 3 , Sr(Na 1/4 Nb 3/4 )O 3 , Ba(Fe y Nb 1-y )O 3 , Ba(Fe y Ta 1-y )O 3 , Ba(Mn y Nb 1-y )O 3 , Ba(Mn y Ta 1-y )O 3 , Ba(Ni y Nb 1-y )O 3 , Ba(Ni y Ta 1-y )O 3 .

8. The method of claim 1 , wherein the substrate comprises a composition selected from the group consisting of a relaxor ferroelectric composition and a normal ferroelectric composition.

9. The method of claim 8 , wherein the substrate is grown by the Bridgman method.

10. The method of claim 8 , wherein the normal ferroelectric composition comprises lead titanate with a composition of PbTiO 3 and the relaxor ferroelectric composition is selected from the group consisting of

lead magnesium niobate with a composition of PbMg 1/3 Nb 2/3 O 3 ,

lead indium niobate with a composition of PbIn 1/2 Nb 1/2 O 3 ,

lead ytterbium niobate with a composition of PbYb 1/2 Nb 1/2 O 3 ,

a mixture of lead magnesium niobate and lead indium niobate, and

a mixture of lead magnesium niobate and lead ytterbium niobate.

11. The method of claim 1 , further comprising removing the PZT single crystal from the substrate.

12. The method of claim 11 , wherein removing the PZT single crystal from the substrate comprises lapping and polishing.

13. A piezoelectric device comprising a PZT single crystal formed according to claim 1 .

14. The piezoelectric device of claim 13 , wherein the piezoelectric device is selected from the group consisting of a transducer, a receiver, a sensor, and an actuator.

15. A system for characterizing pipelines through in-line inspection comprising a piezoelectric device of claim 14 , wherein the piezoelectric device is a transducer and/or a receiver.

16. The system according to claim 15 , wherein the pipeline is configured to transport a substance selected from the group consisting of a liquid and a gas.

17. The method of claim 1 , wherein the PZT comprises less than 10 molar percent ionic dopants.

Assignments (4)
MERGER Recorded Sep 16, 2025
From: QUEST INTEGRATED, LLC
To: QUEST INTEGRITY USA, LLC
Reel/Frame 073445/0113 →
MERGER Recorded Jul 11, 2024
From: QUEST INTEGRATED, LLC
To: QUEST INTEGRITY USA, LLC
Reel/Frame 067958/0129 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 7, 2017
From: QUEST INTEGRATED, INC.
To: QUEST INTEGRATED, LLC
Reel/Frame 042934/0617 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 26, 2015
From: FRATELLO, VINCENT
To: QUEST INTEGRATED, INC.
Reel/Frame 035042/0363 →
Continuity (3)
Provisional Application 61774139 · Mar 7, 2013
Provisional Application 61732062 · Nov 30, 2012
Related Publication 20150233015A1 · Aug 20, 2015