US3710353A
Expired / Lapsed
US
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Thermal capacitative-ferroelectric storage device
Assignee: International Business Machines Corp
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Filing: 1971-12-30
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Granted: 1973-01-09
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Expires: 1991-12-30
Abstract
Abstract A data storage apparatus comprising a memory element having a ferroelectric region in contact with a thermal capacitive region, the thermal capacitive region being a region exhibiting a change in capacitance with a change in temperature sufficient that when a voltage is applied across a selective volume of the memory element, and energy is applied to the thermal capacitive region, a voltage transfer occurs from the thermal capacitive region to the ferroelectric region, resulting in a net voltage across the ferroelectric region capable of causing polarization reversal, or switching of the state of polarization of the ferroelectric region. By measuring current during the switching process, a determination is made whether the region was or was not switched resulting in knowledge of the prior state of polarization of the region and hence, whether a ''''zero'''' or a ''''one'''' was previously stored in the region. Reading may also be done by optical polarization reading techniques.
Inventors
- 👤 B Silverman
- 👤 J Jacobs
- 👤 K Keester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:57
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/047; G11C11/00; G11C11/21; G11C11/22
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
145 words
A data storage apparatus comprising: a memory element having a ferroelectric region in electrical contact with a thermal capacitive region, means for applying a voltage across a selected volume of the memory element, and means for applying energy to the thermal capacitive region of the memory element at the selected volume causing at least a portion of the voltage across the thermal capacitive region to be transferred across the ferroelectric region, the applied voltage and applied energy concurrently chosen to increase the total voltage appearing across the ferroelectric region during only the application of the applied energy to exceed the voltage for ferroelectric polarization reversal in that region, to reverse the state of ferroelectric polarization in that ferroelectric region when that polarity state is opposite the applied voltage polarity, and means for detecting the state of polarization of the selected volume of the ferroelectric region.
Claim 2
Dependent Claim
145 words
A data storage apparatus comprising: a memory element having a ferroelectric region in electrical contact with a thermal capacitive region, means for applying a voltage across a selected volume of the memory element, and means for applying energy to the thermal capacitive region of the memory element at the selected volume causing at least a portion of the voltage across the thermal capacitive region to be transferred across the ferroelectric region, the applied voltage and applied energy concurrently chosen to increase the total voltage appearing across the ferroelectric region during only the application of the applied energy to exceed the voltage for ferroelectric polarization reversal in that region, to reverse the state of ferroelectric polarization in that ferroelectric region when that polarity state is opposite the applied voltage polarity, and means for detecting the state of polarization of the selected volume of the ferroelectric region.
Claim 3
Dependent Claim
20 words
The data storage apparatus of claim 1 wherein the thermal capacitive region is of a material having a dielectric anomaly.
Claim 4
Dependent Claim
22 words
The data storage apparatus of claim 2 including means for maintaining the memory element at a temperature below the anomaly region temperature.
Claim 5
Dependent Claim
21 words
The data storage apparatus of claim 1 wherein the thermal capacitive region is of a ferroelectric material having a dielectric anomaly.
Claim 6
Dependent Claim
29 words
The data storage apparatus of claim 1 wherein the thermal capacitive region is of a material chosen from the group consisting of triglycine sulphate, Rochelle salt and triglycine selanate.
Claim 7
Dependent Claim
40 words
The data storage apparatus of claim 1 wherein the ferroelectric region is of a material chosen from the group consisting of ferroelectric perovskite and ferroelectric oxide materials, lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O15, and PbMg1/3Nb2/3O3, Bi4Ti3O12.
Claim 8
Dependent Claim
40 words
The data storage apparatus of claim 1 wherein the ferroelectric region and the thermal capacitive region are of the same material chosen from the group consisting of lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O15, and PbMg1/3Nb2/3O3, Bi4Ti3O12.
Claim 9
Dependent Claim
31 words
The data storage apparatus of claim 1 including means for concurrently addressing any one of a selected number of selected volumes concurrently with the applied voltage means and applied energy means.
Claim 10
Dependent Claim
17 words
The data storage apparatus of claim 1 wherein the applied energy means is a laser energy source.
Claim 11
Dependent Claim
18 words
The data storage apparatus of claim 1 wherein the applied energy means is a thermal energy generating means.
Claim 12
Dependent Claim
22 words
The data storage apparatus of claim 1 wherein the ferroelectric region and the thermal capacitive region are of the same ferroelectric material.
Claim 13
Dependent Claim
24 words
The data storage apparatus of claim 1 wherein the means for applying energy is sufficient to raise the ferroelectric region above its Curie point.
Claim 14
Dependent Claim
32 words
The data storage apparatus of claim 1 wherein the detecting means comprises means for determining the current flow at any selected volume during the application of the applied energy and applied voltage.
Claim 15
Dependent Claim
27 words
The data storage apparatus of claim 1 wherein the detecting means comprises optical means for determining the polarization state of any selected volume of the ferroelectric region.
Claim 16
Dependent Claim
57 words
A memory element for use in a ferroelectric data storage system whereby the concurrent application of energy and voltage to a selected volume of the memory element causes a change in the state of the polarization of the element, the improvement comprising a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region.
Claim 17
Dependent Claim
57 words
A memory element for use in a ferroelectric data storage system whereby the concurrent application of energy and voltage to a selected volume of the memory element causes a change in the state of the polarization of the element, the improvement comprising a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region.
Claim 18
Dependent Claim
20 words
The data storage apparatus of claim 15 wherein the thermal capacitive region is of a material having a dielectric anomaly.
Claim 19
Dependent Claim
21 words
The data storage system of claim 15 wherein the thermal capacitive region is of a ferroelectric material having a dielectric anomaly.
Claim 20
Dependent Claim
29 words
The data storage system of claim 15 wherein the thermal capacitive region is of a material chosen from the group consisting of triglycine sulphate, Rochelle salt and triglycine selanate.
Claim 21
Dependent Claim
41 words
The data storage system of claim 15 wherein the ferroelectric region is of a material chosen from the group consisting of ferroelectric perovskite and ferroelectric oxide materials, lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O15, and PbMg1/3Nb2/3O3, and Bi4Ti3O12.
Claim 22
Dependent Claim
41 words
The data storage system of claim 15 wherein the ferroelectric region and the thermal capacitive region are of the same material chosen from the group consisting of lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O15, and PbMg1/3Nb2/3O3, and Bi4Ti3O12.
Claim 23
Dependent Claim
22 words
The data storage system of claim 15 wherein the ferroelectric region and the thermal capacitive region are of the same ferroelectric material.
Claim 24
Independent Claim
127 words
The method of reading data in a ferroelectric material comprising: applying a voltage across a selected volume of a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region, the total applied voltage capable to at least cause polarization reversal in the ferroelectric region while the voltage drop across that region is incapable for such reversal, applying energy to the thermal capacitive region to increase the dielectric constant of the thermal capacitive region to transfer at least a portion of the voltage across the thermal capacitive region to the ferroelectric region to increase the voltage across the ferroelectric region to cause polarization reversal in that region when that polarity is opposite the applied voltage polarity, and detecting the polarity of the selected volume.
Claim 25
Independent Claim
127 words
The method of reading data in a ferroelectric material comprising: applying a voltage across a selected volume of a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region, the total applied voltage capable to at least cause polarization reversal in the ferroelectric region while the voltage drop across that region is incapable for such reversal, applying energy to the thermal capacitive region to increase the dielectric constant of the thermal capacitive region to transfer at least a portion of the voltage across the thermal capacitive region to the ferroelectric region to increase the voltage across the ferroelectric region to cause polarization reversal in that region when that polarity is opposite the applied voltage polarity, and detecting the polarity of the selected volume.
Claim 26
Dependent Claim
18 words
The method of claim 22 wherein the thermal capacitive region is of a material having a dielectric anomaly.
Claim 27
Dependent Claim
23 words
The method of claim 23 including the step of maintaining the memory element at a temperature just prior to the anomaly region temperature.
Claim 28
Dependent Claim
19 words
The method of claim 22 wherein the thermal capacitive region is of a ferroelectric material having a dielectric anomaly.
Claim 29
Dependent Claim
28 words
The method of claim 22 wherein the thermal capacitive region is of a material chosen from the group consisting of a triglycine sulphate, Rochelle salt and triglycine selanate.
Claim 30
Dependent Claim
39 words
The method of claim 22 wherein the ferroelectric region is of a material chosen from the group consisting of ferroelectric perovskite and ferroelectric oxide materials, lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O30, and PbMg1/3Nb2/3O3, and Bi4Ti3O12.
Claim 31
Dependent Claim
39 words
The method of claim 22 wherein the ferroelectric region and the thermal capacitive region are of the same material chosen from the group consisting of lead zirconate-lead titanate, barium titanate, barium strontium titanate, Sr4KLiNb10O30, SrKNb5O30, and PbMg1/3Nb2/3O3, and Bi4Ti3O12.
Claim 32
Dependent Claim
35 words
The method of claim 22 including the step of concurrently addressing any one of a selected number of selected volumes concurrently with the application of voltage and the application of energy to that selected volume.
Claim 33
Dependent Claim
20 words
The method of claim 22 wherein the ferroelectric region and the thermal capacitive region are of the same ferroelectric material.
Claim 34
Dependent Claim
26 words
The method of claim 22 wherein applying energy to the thermal capacitive region is additionally sufficient to raise the associated ferroelectric region above its Curie point.
Claim 35
Dependent Claim
33 words
The method of claim 22 wherein detecting the polarity of a selected volume is by determining the current flow at any collected volume during the application of the applied energy and applied voltage.
Claim 36
Dependent Claim
29 words
The method of claim 22 wherEin detecting the polarity of the selected volume is by optically detecting the polarization state region of any selected volume of the ferroelectric region.
Claim 37
Independent Claim
118 words
The method of writing data in a ferroelectric material comprising: applying a voltage across a selected volume of a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region, the total applied voltage capable to cause polarization reversal in the ferroelectric region while the voltage drop across that region is incapable for such reversal, and applying energy to the thermal capacitive region to increase the dielectric constant of the thermal capacitive region to transfer at least a portion of the voltage across the thermal capacitive region to the ferroelectric region to increase the voltage across the ferroelectric region to cause polarization reversal in that region when that polarity is opposite the applied voltage polarity.
Claim 38
Independent Claim
118 words
The method of writing data in a ferroelectric material comprising: applying a voltage across a selected volume of a memory element comprising a thermal capacitive region in electrical contact with a ferroelectric region, the total applied voltage capable to cause polarization reversal in the ferroelectric region while the voltage drop across that region is incapable for such reversal, and applying energy to the thermal capacitive region to increase the dielectric constant of the thermal capacitive region to transfer at least a portion of the voltage across the thermal capacitive region to the ferroelectric region to increase the voltage across the ferroelectric region to cause polarization reversal in that region when that polarity is opposite the applied voltage polarity.
References Cited (Backward Citations)
US3148354A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |