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US4391901A Expired / Lapsed US ⏱️ 0.0 years remaining

Photosensitivity enhancement of PLZT ceramics by positive ion implantation

Assignee: AT&T Inc
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Filing: 1982-01-28
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Granted: 1983-07-05
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Expires: 2002-01-28
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Abstract

Abstract The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and non-volatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Implanted ions include H+, He+, Ne+, Ar+, as well as chemically reactive ions from Fe, Cr, and Al. The positive ion implantation advantageously serves to shift the absorption characteristics of the PLZT material from near-UV light to visible light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to the positive ions at sufficient density, from 1x1012 to 1x1017, and with sufficient energy, from 100 to 500 KeV, to provide photosensitivity enhancement. The PLZT material may have a lanthanum content ranging from 5 to 10%, a lead zirconate content of 62 to 70 mole %, and a lead titanate content of 38 to 30%. The ions are implanted at a depth of 0.1 to 2 microns below the surface of the PLZT plate.

Inventors

  • 👤 Cecil E. Land
  • 👤 Paul S. Peercy

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 03:26
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/725; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/055; G02F1/0558; G11; G11C; G11C13/00; G11C13/04; G11C13/047; Y; Y10; Y10S; Y10S430/00; Y10S430/163

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 88 words
In a lead lanthanum zirconate titanate (PLZT) ceramic plate used for a photoferroelectric image storage and display device, the improvement comprising: the PLZT ceramic having a near surface region implanted with positive ions to provide enhanced photosensitivity of the plate in the near-UV spectrum, wherein said ions are selected from the group consisting of helium ions, hydrogen ions, argon ions, neon ions, aluminum ions, chromium ions, and iron ions, and are implanted below the surface of said PLZT plate at a depth of from 0.1 to 2 microns.
Claim 2
Dependent Claim 88 words
In a lead lanthanum zirconate titanate (PLZT) ceramic plate used for a photoferroelectric image storage and display device, the improvement comprising: the PLZT ceramic having a near surface region implanted with positive ions to provide enhanced photosensitivity of the plate in the near-UV spectrum, wherein said ions are selected from the group consisting of helium ions, hydrogen ions, argon ions, neon ions, aluminum ions, chromium ions, and iron ions, and are implanted below the surface of said PLZT plate at a depth of from 0.1 to 2 microns.
Claim 3
Dependent Claim 31 words
The PLZT ceramic plate of claim 1 wherein the implanted ions are selected from the group consisting of H + , He + , Ar + , and Ne + .
Claim 4
Dependent Claim 26 words
The PLZT ceramic plate of claim 1 wherein the ions implanted are chemically-reactive ions provided by elements of the group consisting of aluminum, chromium, and iron.
Claim 5
Dependent Claim 34 words
The PLZT ceramic plate of claim 2 wherein the implanted ions consist of Ar + coimplanted with other ions selected from the group consisting of He + , Ne + , and mixtures thereof.
Claim 6
Dependent Claim 34 words
The PLZT ceramic plate of claim 3 wherein the chemically-reactive ions selected are coimplanted with ions selected from the group consisting of Ar + , Ne + , He + , and mixtures thereof.
Claim 7
Dependent Claim 29 words
The PLZT ceramic plate of claim 1 wherein the lanthanum is in the range from 5 to 10 and the ratio of zirconium titanium ranges from 62/38 to 70/30.
Claim 8
Dependent Claim 25 words
The PLZT ceramic plate of claim 1 wherein said ions are implanted with a density ranging from 1×10 12 to 1×10 17 ions/cm 2 .
Claim 9
Dependent Claim 24 words
The PLZT ceramic plate of claim 1 wherein the energy of implantation of said ions is within the range from 100 to 500 keV.
Claim 10
Dependent Claim 26 words
The PLZT ceramic plate of claim 5 wherein said plate has ions of sufficient density and energy implanted to be sensitive to the visible light spectrum.
Claim 11
Dependent Claim 40 words
An article as described in claim 9 wherein said positive ions are selected from the group consisting of H + , He + , Ne + , Ar + , ions coimplanted with Fe, Al and Cr, and mixtures thereof.
Claim 12
Dependent Claim 27 words
The PLZT ceramic plate of claim 1 wherein said PLZT ceramic being treated included both antiferroelectric phase material and ferroelectric phase material to provide increased overall contrast.

References Cited (Backward Citations)

US3978458A Cited
US3868653A Cited
US4135224A Cited
US4158201A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-07-04 1987-01-03 1987-07-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-07-04 1991-01-03 1991-07-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-07-04 1995-01-03 1995-07-05 $7700.00 Window Closed / Lapsed

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