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Demonstrates the alignment of defect dipoles along the direction of the spontaneous polarization in polycrystalline Pb(Zr,Ti)O[sub3] and BaTiO[sub3] ferroelectric ceramics using electron paramagnetic resonance. Components of net polarization; Information on several defect dipoles; Evidence for defect-dipole alignment in polycrystalline ceramics; Description of lead ion displacements.

Presents a study which focused on polarization suppression in lead(zirconium, titanium)oxygen[sub3] thin films. Occurrence of optical suppression effect; Methods; Results and discussion.

Presents a study which determined the spatial density and energy distribution of grain boundary electronic states in Bi-Co-ZnO and Pr-Co-Al-ZnO varistors. Physical origin of the trap states; Information on the current-voltage characteristics for the varistors; Densities of states found in the varistors.

Attempts to provide experimental evidence for the existence of impact ionized holes in n-type zinc oxide varistors of several chemical compositions when they are in their breakdown condition. Information on the chemical composition of noncommercial varistors; Discussion on the luminescence measurement technique; Behavior of the band-gap electroluminescence.

Previous research on composite systems has cast doubt on their potential to produce a good likeness. Poor memory of the target's face and problems in translating a verbal description into a visual mental image were examined as possible reasons for this. A computerized composite system was used to construct facial images of famous individuals. Results indicated that a reasonable number of composites were identified overall. Composites produced directly by the “operators” tended to be more accurate than those produced via “describers”. In addition, composites produced via describers, but not those directly by operators, were less accurate when created from memory than when a photograph was provided. This suggests that verbal descriptions, as well as facial memory, may limit composite accuracy. [ABSTRACT FROM AUTHOR]

Determines the response of highly nonlinear zinc oxide (ZnO) varistor material to electrically perturbing inclusions, using a numerical computation of current density distribution. Assessment of nonconductive spheres and disks, which resemble inclusion shapes observed in chemically prepared varistor material; Properties of varistors; Details of the numerical computation of current density distribution.

We report on the thermally activated hysteresis relaxation effects in (La,Sr)CoO3/ (Pb,La)(Zr,Ti)O3/(La,Sr)CoO3 thin film ferroelectric capacitors. Films cooled in oxygen deficient ambients exhibit a marked voltage offset in the hysteresis loops. Upon the application of a dc bias voltage or unidirectional pulses of the same polarity as the offset, the loops become more symmetric. Subsequently, holding the capacitors in the original preferred polarization state leads to a relaxation of the hysteresis loop towards its original voltage offset condition. The relaxation process is described by a stretched exponential and is thermally activated. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]