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Lead zirconate titanate
About: Lead zirconate titanate is a research topic. Over the lifetime, 7141 publications have been published within this topic receiving 150878 citations.
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TL;DR: In this paper, the extrinsic contribution to the dielectric constant of PZT films was mainly attributed to 180° domain wall motion, which increased with both film thickness and grain size.
Abstract: In this article, domain wall motion and the extrinsic contributions to the dielectric and piezoelectric responses in sol–gel derived lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were investigated. It was found that although the films had different thicknesses, grain sizes, and preferred orientations, similar intrinsic dielectric constants were obtained for all films between 0.5 and 3.4 μm thick. It was estimated that about 25%–50% of the dielectric response at room temperature was from extrinsic sources. The extrinsic contribution to the dielectric constant of PZT films was mainly attributed to 180° domain wall motion, which increased with both film thickness and grain size. In studies on the direct and converse longitudinal piezoelectric coefficients of PZT films as a function of either stress or electric driving field, it was found that the ferroelastic non-180° domain wall motion was limited. Thus extrinsic contributions to the piezoelectric response were small in fine grain PZT films (especially those under 1.5 μm in thickness). However, as the films became thicker (>5μm), nonlinear behavior between the converse piezoelectric coefficient and the electric driving field was observed. This indicated that there was significant ferroelectric non-180° domain wall motion under high external excitation in thicker films. The activity of the non-180° domain walls was studied through non-180° domain switching. For fine grain films with film thicknesses less than 2 μm, non-180° switching was negligible. Transmission electron microscopy plan-view micrographs evidenced non-180° domain fringes in these films, where the vast majority of grains were 50–100 nm in diameter and showed a single set of domain fringes. Taken together, these measurements suggest that the pinning of non-180° domain walls is very strong in films with thickness less than 2 μm. In thicker films, non-180° domain switching was evidenced when the poling field exceeded a threshold field. The threshold field decreased with an increase in film thickness, suggesting more non-180° domain wall mobility in thicker films. Non-180° domain switching in large grained PZT films was found to be much easier and more significant than in the fine grained PZT films.
480 citations
TL;DR: By combining Auger data on the width of an oxygen depletion layer near the Pt electrodes with a modified Langmuir-Child law for the leakage current, this paper deduced parameters related to the space charge density and field in 210nm-thick PbZr1−xTixO3 memories.
Abstract: By combining Auger data on the width of an oxygen depletion layer near the Pt electrodes with a modified Langmuir–Child law for the leakage current: I(V) = aV + bV2, we deduce parameters related to the space‐charge density and field in 210‐nm‐thick PbZr1−xTixO3 memories. The results are compared with the space charge fields inferred by Okazaki (∼10 kV/cm for PZT), which involve measuring the switching speeds ts(E) for positive and negative voltages. Differences in the voltage dependencies of the leakage current are found after fatigue and are related to specific electrochemical processes involving oxygen deposition on electrode surfaces.
474 citations
TL;DR: A review of the current trends and historical development of piezoelectric sensors and sensor materials technology can be found in this paper, where a discussion of the bases of piezo and ferroelectric activity is discussed.
Abstract: This paper reviews the current trends and historical development of piezoelectric sensors and sensor materials technology. It begins with a discussion of the bases of piezo- and ferroelectric activity, followed by an overview of the most commonly used piezoelectric ceramic: lead zirconate titanate (PZT). A discussion of the properties and applications of piezoelectric crystals and additional piezoelectric ceramics is followed by a description of several sensor configurations prepared from bulk ceramics. An extensive review and comparison of piezoelectric ceramic—polymer composite sensors based on the connectivity of the constituent phases is also presented. We conclude our discussion of sensor configurations with recent examples of piezoelectric ceramic—metal composite sensors, and expected future developments in the area of piezoelectric sensors.
471 citations
TL;DR: In this article, the authors measured coercive field and switching voltage versus thickness in PbZr0.54Ti0.46O3 thin (0.15-0.50 μm) films, together with switching times and current transient shapes versus field and temperature.
Abstract: We have measured coercive field and switching voltage versus thickness in PbZr0.54Ti0.46O3 thin (0.15–0.50 μm) films, together with switching times and current transient shapes versus field and temperature. The results show activation fields of order 120 kV/cm at room temperature, threshold voltages below 1.3 V, and switching speeds faster than 100 ns, demonstrating that fast, nonvolatile memories can be constructed that are compatible with standard silicon or GaAs integrated circuit voltage levels, without the need for an internal voltage pump. The displacement current transient data yield 2.5 as the dimensionality of domain growth if one‐step intial nucleation rate is assumed, and are compatible with the theory of Ishibashi, yielding imaxtmax/Ps=1.65±0.23, in comparison with the predicted 1.646. The switching time exhibits an activation field dependence upon both voltage and temperature through a single reduced parameter (TC−T)(VTC),−1 in accord with the theory of Orihara and Ishibashi.
407 citations
TL;DR: The theory and data for magnetoelectric (ME) coupling at electromechanical resonance (EMR) in the layered samples were investigated in this article, and the results showed that the ME voltage coefficient at resonance increases by a factor of 40 compared to low frequency values.
Abstract: Magnetoelectric interactions in bilayers of magnetostrictive and piezoelectric phases are mediated by mechanical deformation. This work is concerned with the theory and companion data for magnetoelectric (ME) coupling at electromechanical resonance (EMR) in the layered samples. Estimated ME voltage coefficient versus frequency profiles for nickel, cobalt, or lithium ferrite and lead zirconate titanate (PZT) predict a giant ME effect at EMR with the highest coupling expected for cobalt ferrite-PZT. There is excellent agreement between the theory and data for layered nickel ferrite-PZT; the ME voltage coefficient at resonance increases by a factor of 40 compared to low frequency values. Similar measurements on layered ferromagnetic alloy-PZT and bulk ferrite-PZT reveal even a stronger EMR assisted enhancement in ME coupling.
398 citations