Claims
- 1. A method for producing an electroceramic material selected from the group consisting of lead zirconate titanate (PZT) and barium strontium titanate (BST), said method comprising:(a) compacting a precursor of said electroceramic material to form a preform, said precursor selected from the group consisting of hydroxides and oxalates of said electroceramic material; (b) thermally treating the preform at a predetermined temperature; (c) re-compacting the preform; and (d) sintering the re-compacted preform to form said electroceramic material.
- 2. A method according to claim 1, wherein the preform is thermally treated at a temperature in the range of 400° C. to 600° C.
- 3. A method according to claim 1, wherein the re-compaction of the preform is carried out in a cold isostatic press.
- 4. A method according to claim 1, wherein sintering of the recompacted preform is carried out at a temperature in the range of 900° C. to 1400° C.
- 5. A method according to claim 1, wherein Pb(Zr0.52Ti0.48)O3 is produced from hydroxide precursors, and wherein the sintering of the re-compacted preform is carried out at a temperature in the range of 900° C. to 1100° C.
- 6. A method according to claim 1, wherein barium strontium titanate is produced from a precursor of oxalates, and wherein the sintering of the re-compacted preform is carried out at a temperature in the range of 1000° C. to 1400° C.
- 7. A method according to claim 6, wherein Ba0.65Sr0.35TiO3 is produced from oxalate precursors, and wherein sintering is carried out at about 1200° C., the relative density of the Ba0.65Sr0.35TiO3 being about 99.4% of theoretical density.
- 8. A method according to claim 1, wherein said lead zirconate titanate has the formula Pb(ZrTi)O3 with Zr:Ti molar ratio ranging from 80:20 to 20:80.
- 9. A method according to claim 1, additionally comprising forming said hydroxide and/or oxalate precursors by coprecipitation of an aqueous solution of preselected cations.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9801396 |
Jun 1998 |
SG |
|
Parent Case Info
International application PCT/SG99/00056 was published under PCT Article 21(2) in English. This application is the national phase of international application PCT/SG99/00056 filed Jun. 4, 1999which designated the U.S.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/SG99/00056 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/64366 |
12/16/1999 |
WO |
A |
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
4283228 |
Buchanan et al. |
Aug 1981 |
A |
5368834 |
Kulwicki et al. |
Nov 1994 |
A |
5433917 |
Srivastava et al. |
Jul 1995 |
A |
5573582 |
Inui et al. |
Nov 1996 |
A |
6093338 |
Tani et al. |
Jul 2000 |
A |
Foreign Referenced Citations (1)
Number |
Date |
Country |
0280033 |
Aug 1988 |
EP |