Optical Imaging and Information Storage in Ion Implanted Ferroelectric Ceramics

1981 ◽  
Vol 7 ◽  
Author(s):  
P. S. Peercy ◽  
C. E. Land
Keyword(s):  
Uv Light ◽  
Visible Spectrum ◽  
Dark Conductivity ◽  
Information Storage ◽  
Ferroelectric Ceramics ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
Photographic Images ◽  
Intrinsic Photosensitivity ◽  
Ion Implanted

ABSTRACTPhotographic images can be stored in ferroelectric-phase lead lanthanum zirconate titanate (PLZT) ceramics using a novel photoferroelectric effect. These images are nonvolatile but erasable and can be switched from positive to negative by application of an electric field. We have found that the photosensitivity of ferroelectric PLZT is dramatically improved by ion implantation into the surface exposed to image light. For example, the intrinsic photosensitivity to near-UV light is increased by as much as four orders of magnitude by coimplantation with Ar and Ne. The increased photosensitivity results from implantation-induced decreases in dark conductivity and dielectric constant in the implanted layer. Furthermore, the increased photoferroelectric sensitivity has recently been extended from the near-UV to the visible spectrum by implants of Al and Cr. Ion-implanted PLZT is the most sensitive, nonvolatile, selectively-erasable image storage medium currently known.

Charge Trapping Centers in Ferroelectric Ceramics

1992 ◽  
Vol 284 ◽  
Author(s):  
C. H. Seager ◽  
W. L. Warren ◽  
B. A. Tuttle ◽  
R. D. Nasby ◽  
D. Dimos
Keyword(s):  
Uv Light ◽  
Charge Trapping ◽  
Ferroelectric Ceramics ◽  
Electrical Measurements ◽  
Lead Lanthanum Zirconate Titanate ◽  
Paramagnetic Resonance ◽  
Lanthanum Zirconate ◽  
Polarization Electric Field ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic

ABSTRACTElectron paramagnetic resonance (EPR), photo-thermal deflection spectroscopy (PDS), and electrical measurements have been used to characterize as-received and UV-lluminated lead lanthanum zirconate titanate (PLZT) and PZT ceramics. Following optical illumination we observe the activation of positively charged Pb+3 and negatively charged Ti+3 ions, as well as an increased broad absorption peak around 2.6 eV. The spatial distribution of the induced absorption correlates well with the location of the absorbed UV, suggesting that photo-produced carrier pairs are trapped at Ti+4 and Pb+2 producing the observed paramagnetism. The Ti+3 EPR spectra were successfully fit using the crystal field parameters derived from the PDS spectra. Preliminary results suggest that these charged paramagnetic ions can influence the electrical properties of PZT thin films. We investigated the effects of UV light and dc bias sequences by polarization-electric field (PE) measurements and find that the coercive fields are dependent on the sign of the applied bias during UV exposure. It is reasonable to expect that Pb+3 and/or Ti+3 ions act as the charge trapping sites which cause the threshold voltage shifts in the PE loop.

Sol-Gel Transparent PLZT Ferroelectric Ceramics

2006 ◽  
Vol 45 ◽  
pp. 2489-2494 ◽  
Author(s):  
M. Płońska ◽  
Wojciech A. Pisarski ◽  
Zbigniew Pędzich ◽  
Zygmunt Surowiak
Keyword(s):  
Infrared Spectroscopy ◽  
Mercury Porosimetry ◽  
Sol Gel ◽  
Ferroelectric Ceramics ◽  
Ceramic Powders ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
Pressing Method ◽  
Fine Grained ◽  
To Receive

Lead lanthanum zirconate titanate (known as PLZT) ceramic powders have been prepared by the modified sol – gel method, and underwent consolidation by the hot uniaxial pressing method. Application of such technique of preparation permitted to receive fine-grained transparent PLZT x/65/35 ceramics, with x = 8 -10 La at.%. The present publication gives a detailed account of the relationships between technology and physical properties of obtained materials. To analyze all ceramics SEM, EDS and mercury porosimetry were performed, and dielectric properties were studied too. Quite wide light transparency from the visible to nearinfrared range for PLZT ceramics was detected using optical absorption and infrared spectroscopy.

Photovoltaic Effect with the Structural Control and its Application to the Optical Sensor

2006 ◽  
Vol 320 ◽  
pp. 61-64
Author(s):  
Masaaki Ichiki ◽  
Harumi Furue ◽  
Takeshi Kobayashi ◽  
Yasushi Morikawa ◽  
Kazuhiro Nonaka ◽  
...  
Keyword(s):  
Optical Sensor ◽  
Structural Control ◽  
Photovoltaic Effect ◽  
Electrical Power ◽  
Dark Conductivity ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
Micro Electro Mechanical Systems ◽  
Oriented Films ◽  
Metalorganic Deposition

Photovoltaic lead lanthanum zirconate titanate films in a layered structure of different crystallographic orientations are fabricated by an optimized metalorganic deposition method. Such films of (001) orientation exhibit a photovoltaic electrical power of approximately 20 times higher than that of random films. The anisotropic optical properties of the oriented films, including dark conductivity, photoconductivity and photovoltaic tensor surfaces, are obtained quantitatively. These results show that the photovoltaic output current and power of the oriented films are highly improved to be equal to those of semiconductors and suitable for application in the optical sensor of micro-electro-mechanical systems.

Effect of Nd3+ concentration quenching in highly doped lead lanthanum zirconate titanate transparent ferroelectric ceramics

2007 ◽  
Vol 101 (5) ◽  
pp. 053111 ◽  
Author(s):  
A. S. S. de Camargo ◽  
C. Jacinto ◽  
L. A. O. Nunes ◽  
T. Catunda ◽  
D. Garcia ◽  
...  
Keyword(s):  
Concentration Quenching ◽  
Ferroelectric Ceramics ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
Zirconate Titanate

Electro-optic phenomena

2004 ◽  
Author(s):  
Robert E. Newnham
Keyword(s):  
Light Intensity ◽  
Electric Field ◽  
Electric Fields ◽  
Communication Systems ◽  
Ferroelectric Ceramics ◽  
Refractive Indices ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
The Third ◽  
Electro Optic

Optical beams can be controlled by manipulating the refractive indices and absorption coefficients with applied electric fields. In communication systems electro-optic effects are used in phase and amplitude modulation, in beam deflectors, and in tunable filters. Three such effects are illustrated in Fig. 28.1. Lead lanthanum zirconate titanate (PLZT) is a transparent electroceramic that can be prepared in several different ferroelectric forms with large electro-optic coefficients. When prepared in a normal ferroelectric form it can be used in two different ways. A light-tunable shutter is constructed by coating a multidomain ceramic of PLZT with a photoconducting layer and transparent electrodes. A bias voltage on the electrodes is transferred to the ceramic when the photoconductor is illuminated. The electric field alters the domain structure and the degree of light scattering, controlling the intensity of light. Fully poled ferroelectric ceramics exhibit the linear electro-optic effect Using planar electrodes the PLZT is poled perpendicular to the optical beam. Polarizer and analyzer are positioned in the ±45◦ positions, and light intensity is controlled by altering the birefringence with an electric field. The third experiment utilizes a pseudo-cubic PLZT composition with a large quadratic electro-optic effect. No poling is required in this case. With polarizer and analyzer again in the ±45◦ positions, the transmitted light intensity is proportional to E2 rather than E. Linear and quadratic electro-optic coefficients are defined in terms of the fieldinduced changes in the optical indicatrix: . . . Bij(E) − Bij(0) = Δ

A Method for Measuring Short Crack R-Curve Behavior of Ferroelectric Ceramic

1999 ◽  
Author(s):  
Wei Chen ◽  
Christopher S. Lynch ◽  
Doru Lupascu
Keyword(s):  
Crack Length ◽  
Surface Crack ◽  
Damage Zone ◽  
Ferroelectric Ceramic ◽  
Ferroelectric Ceramics ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
Linear Elastic ◽  
Four Point Bending ◽  
Knoop Indentation

Abstract This work describes a method for measurement of R-curve behavior in ferroelectric ceramics using four point bending specimens with a controlled surface crack. A short surface crack is produced by a Knoop indentation and the damage zone is polished away. The results are compared for two compositions of lead lanthanum zirconate titanate (PLZT), an elastio-plastic ferroelectric composition and a linear elastic electrostrictive composition. R-curves are measured in the crack length regime of 0.1 to 0.8 mm. The ferroelastic composition displays a toughness increase from 0.7 to 1.4 MPam. The linear elastic composition displays a constant toughness of between 0.6 and 0.7 MPa√m. The R-curve behavior of PLZT 8/65/35 is attributed to ferroelastic toughening.

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