US5736759A
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Reduced fatigue ferroelectric element
Assignee: NEC Corp
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Filing: 1996-07-24
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Granted: 1998-04-07
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Expires: 2016-07-24
Abstract
Abstract A fatigue resistent ferroelectric element having a ferroelectric body, and regions of enhanced oxide ion mobility on opposite sides of the body to which are attached electrodes. In one embodiment, an element made from the known ferroelectric material PZT is treated at each of two surfaces where the electrodes are to be attached with a fast ion conductor, such as doped yttria stabilized zirconia. In another embodiment, a ferroelectric element constructed essentially of strontium tantalite (SrTaO6) has each of its surfaces where electrodes are to be attached treated with bismuth oxide (Bi2O3) that is then diffused into surface regions of the element during an annealing process.
Inventors
- 👤 Robert C. Haushalter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:29
CPC Classifications
H; H10; H10B; H10B12/00; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/684
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
58 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 , such that the mobility of oxide ions in the ferroelectric element is enhanced.
Claim 2
Dependent Claim
58 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 , such that the mobility of oxide ions in the ferroelectric element is enhanced.
Claim 3
Dependent Claim
98 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 such that the mobility of oxide ions in the ferroelectric element is enhanced and in which the ferroelectric element is essentially one selected from the Perovskite-type compounds consisting of: Barium titanate, Lead titanate, Strontium titanate, Cadmium titanate, Sodium niobate, Potassium niobate, Sodium tantalate, Bismuth ferrite, Potassium iodate, Caesium germanium chloride, Silver niobate, Silver tantalate.
Claim 4
Dependent Claim
98 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 such that the mobility of oxide ions in the ferroelectric element is enhanced and in which the ferroelectric element is essentially one selected from the Perovskite-type compounds consisting of: Barium titanate, Lead titanate, Strontium titanate, Cadmium titanate, Sodium niobate, Potassium niobate, Sodium tantalate, Bismuth ferrite, Potassium iodate, Caesium germanium chloride, Silver niobate, Silver tantalate.
Claim 5
Dependent Claim
66 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 such that the mobility of oxide ions in the ferroelectric element is enhanced and in which the ferroelectric element is essentially PZT.
Claim 6
Dependent Claim
66 words
A ferroelectric device comprising a ferroelectric element having a pair of opposed surfaces and a pair of electrodes on said opposed surfaces wherein regions of the ferroelectric element that are adjacent to the electrodes are rich in doped Y 2 O 3 /ZrO 2 such that the mobility of oxide ions in the ferroelectric element is enhanced and in which the ferroelectric element is essentially PZT.
Claim 7
Dependent Claim
21 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially one selected from the Lithum-niobate-type compounds.
Claim 8
Dependent Claim
21 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially one selected from the Tungsten-bronze-type oxides.
Claim 9
Dependent Claim
21 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially one selected from the Pyrochlore-type compounds.
Claim 10
Dependent Claim
21 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially one selected from the layer-structure oxides.
Claim 11
Dependent Claim
21 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially one selected from the barium-fluoride-type compounds.
Claim 12
Dependent Claim
18 words
A ferroelectric device in accordance with claim 1 in which the ferroelectric element is essentially a manganite compound.
Claim 13
Independent Claim
72 words
A method of manufacturing a ferroelectric device comprising the steps of: forming, in a ferroelectric element having opposite surfaces, regions rich in doped Y 2 O 3 /ZrO 2 , that enhances the mobility of oxide ions in the ferroelectric element wherein said regions are formed adjacent to said opposite surfaces; attaching electrodes to each of said regions; and treating said device such that said regions are interdiffused with said ferroelectric element.
Claim 14
Independent Claim
72 words
A method of manufacturing a ferroelectric device comprising the steps of: forming, in a ferroelectric element having opposite surfaces, regions rich in doped Y 2 O 3 /ZrO 2 , that enhances the mobility of oxide ions in the ferroelectric element wherein said regions are formed adjacent to said opposite surfaces; attaching electrodes to each of said regions; and treating said device such that said regions are interdiffused with said ferroelectric element.
Claim 15
Dependent Claim
15 words
The method according to claim 10 wherein said treating step includes annealing said ferroelectric device.
References Cited (Backward Citations)
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