Electrostrictive materials based on doped ceria

Patent metadata

Field	Value
Publication number	US-2024300821-A1
Application number	US-202418668340-A
Country	US
Kind code	A1
Filing date	May 20, 2024
Priority date	Nov 21, 2021
Publication date	Sep 12, 2024
Grant date	—

Abstract

This invention provides doped ceria-based materials exhibiting electrostriction properties and methods of preparation thereof.

First claim

What is claimed is:

1 . A ceria-based material, doped by a metal M, said metal M is selected from Hf, Zr and Ti, wherein upon application of an electric field said ceria-based material generates displacement, stress or a combination thereof, wherein the electrostriction coefficient of said material ranges between 10 −15 m 2 /V 2 and 10 −18 m 2 /V 2 at a frequency ranging between 0.1 Hz and 105 Hz.

2 . The material of claim 1 , wherein said material is represented by the formula Ce 1-x M x O 2-d wherein x ranges between 0.02 and 0.7 and d ranges between 0 and 0.03.

3 . The material of claim 1 , co-doped with a metal with a lower valence than said metal M.

4 . The material of claim 3 , wherein said metal with a lower valence is selected from: Ca, Mg, Fe, Sc, Sn and Y or combinations thereof.

5 . The material of claim 3 , wherein said metal with a lower valence comprises a lanthanide L.

6 . The material of claim 4 , wherein said lanthanide L is any lanthanide selected from La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu or any combination thereof.

7 . The material of claim 6 , wherein said ceria-based material is represented by the formula Ce 1-x-y M x L y O 2-y/2-d , and wherein said x ranges between 0.01-0.7 and said y range between 0.01-0.7 and said d ranges between 0 and 0.03.

8 . The material of claim 7 , wherein L is La or Yb.

9 . The material of claim 8 , wherein L is La, x=0.10±0.02 and y ranges between 0.01 and 0.08, or wherein L is Yb, x=0.10±0.02 and y ranges between 0.05 and 0.15.

10 . The material of claim 1 , wherein said displacement ranges between 0.1 ppm and 500 ppm.

11 . The material of claim 1 , wherein said stress is at least 0.01 MPa.

12 . The material of claim 1 , with a Young's modulus which ranges between 100 GPa and 250 GPa.

13 . The material of claim 1 , wherein said electrostriction coefficient is frequency independent.

14 . The material of claim 1 , with a dielectric constant which ranges between 10 and 1000.

15 . The material of claim 1 , with an electrical conductivity which ranges between 10 −9 S/m and 10 −5 S/m.

16 . The material of claim 1 , in a material form selected from: a disk, a film, a powder, a bar, a pellet or any combinations thereof.

17 . A process for making the material of claim 1 , said process comprising:
a. adding an alkaline aqueous solution to an aqueous solution containing Ce ions, ions of metal M and optionally ions of a metal L; b. keeping the resulting mixture at an elevated temperature, optionally while stirring, for a period of time of at least 25 mins; and c. optionally washing the resulted precipitate.

18 . The process of claim 17 , wherein the origin of the Ce ions, the metal M ions and optionally the metal Lions is a salt of said ions.

19 . The process of claim 18 , wherein the salts of said ions are Ce(NO 3 ) 3 ·6H 2 O, ZrO(NO 3 ) 2 ·6H 2 O, and optionally L(NO 3 ) 3 ·6H 2 O.

20 . The process of claim 17 , wherein said alkaline aqueous solution comprises (NH 4 ) 2 CO 3 .

21 . The process of claim 17 , wherein the resultant precipitate is a powder, and wherein said powder is ground and optionally calcined.

22 . The process of claim 21 , wherein said powder undergoes pressing in a mold or die, resulting in the formation of a disk, bar or a pellet.

Assignees

• Yeda Res & Dev

Inventors

• Lubomirsky Igor
• Varenik Maxim

Classifications

• C01P2006/40

  Electric properties · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2002/52

  containing elements as dopants · CPC title

• C01G25/006

  Compounds containing zirconium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C04B2235/327

  Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof · CPC title