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Using Ginzburg-Landau theory and two-dimensional (2D) phase field simulations, we analyze the influence of flexoelectric coupling on the domain patterns in ferroelectrics. The phase field simulations predict that a high strength of the flexoelectric coupli ...

Relaxor Pb(Sc1/2Nb1/2)O-3 (PSN) thin films without pyrochlore phase were processed from the modified alkoxide solution precursors. The preparation of single phase PSN thin films has a narrow processing window due to the appearance of an undesirable pyrochlore phase and volatility of PbO. Thin film processing has been improved through selection of precursor solutions, heat treatment and optimized deposition-condition are optimized. Especially, the effects of Pt substrates seeded with additional layers upper

The dependence of the formation of ferroelastic stripe domain patterns on the thermal history is investigated by detailed piezoresponse force microscopy and X-ray diffraction experiments after and during annealing of tensile strained tetragonal Pb(Ti,Zr)O- ...

The switching of the sandwich structure ''ferroelectric+thin dielectric layer'' is theoretically studied. The behavior of the remanent polarization, P-r, coercive field, E(c), maximal polarization on the loop, P-s, and the slope of the hysteresis loop at E(c) as a function of both, the relative thickness of the layer (the thickness of the dielectric divided by the thickness of the ferroelectric) and the amplitude of the measuring field, is analyzed. It is shown that the effect of the layer on P-r and the sl

Direct measurements of longitudinal (d(33)) and transverse (d(31)) piezoelectric coefficients have been made on cuboid samples of 001-poled 0.955Pb[Zn1/3Nb2/3]O-3-0.045PbTiO(3) (PZN-4.5PT) and 0.68Pb[Mg1/3Nb2/3]O-3-0.32PbTiO(3) (PMN-32PT) single crystals. The measurements were made in a Berlincourt-type press over a wide range of dynamic and static bias stresses. In the transverse mode, the response was found to be essentially anhysteretic and d(31) was independent of the dynamic stress amplitude. In c

Bismuth-based layered compounds have been considered during the last years as interesting materials fur high temperature piezoelectric applications, due to their stability and wide thermal range of the ferroelectric activity. The high electrical conductivity present at high temperatures has been a disadvantage for the potential applications of these compounds. On Bi4Ti3O12 (BIT), different doping such as Nb5+ and W6+ were used to increase resistivity. It has been shown that Nb5+ doping modifies piezoelectri

The printing of lead zirconate titanate (PZT, Pb(Zr,Ti)O-3) piezoelectric thick films on silicon substrates is being studied for potential use as microactuators, microsensors, and micro.. transducers. A fundamental challenge in the fabrication of useful PZT thick-film devices on silicon is to sinter the PZT to high density at sufficiently low temperature to avoid mechanical or chemical degradation of the silicon substrate. The goal of the present study is to develop and implement suitable electrodes and PZT

The lead magnesium niobate [Pb(Mg1/3Nb2/3)O-3 or PMN], and its solid solutions with lead titanate (PbTiO3 or PT), are of great interest because of their high electromechanical properties. At large PMN content, these materials exhibit relaxor characteristics with large electrostrictive strains and a large permittivity, while compositions near the morphotropic phase boundary present very interesting piezoelectric properties. So far, properties of these materials in ceramic, thin film and single-crystal form h

This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-mu m-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus par ...

Dielectric breakdown of (Pb,La)(Zr,Ti)O-3(PLZT) film capacitors with Pt and SrRuO3 electrodes, in its initial or virgin state and after voltage cycling that causes polarization fatigue, is studied by constant-current measurements. It is shown that for different types of PLZT capacitors, the breakdown onset is controlled by the critical charge flown through the film (charge to breakdown) rather than the voltage applied to the capacitor. The charge to breakdown for the asymmetrical Pt/SrRuO3/PLZT/Pt capacitor

Polarization reversal in ferroelectric nanomesas of polyvinylidene fluoride with trifluoroethylene has been probed by ultrahigh vacuum piezoresponse force microscopy in a wide temperature range from 89 to 326 K. In dramatic contrast to the macroscopic data ...

Sodium yttrium calcium-oxyhydroxyapatites powders with compositions of {Ca9.98-0.9xY0.9Na0.02(6)[(OH)(1.98-0.9x)O(0.9)square(0.02)],x=0.1.0(here square denotes vacancies at OH lattice sites} were synthesized by the wet process. Porous (Ca, Y, Na)-Ap (here Ap denotes apatite) ceramics having apparent porosities of around 33% were prepared at high temperature under steam flow. On the basis of the results of X-ray diffraction, all the obtained ceramics exhibited almost single-phase (Ca, Y, Na)-Ap with h

Thin epitaxial films have a great potential to be used in real life applications, such as oxide-on-silicon. However, they often contain a large amount of defects, leading to an enhanced electrical conductivity. This could be desirable in some applications ...

In the pursuit of ferroic-based (nano) electronics, it is essential to minutely control domain patterns and domain switching. The ability to control domain width, orientation and position is a prerequisite for circuitry based on fine domains. Here, we deve ...

The structural phase diagram of the Pb-free ferroelectric (Na1/2Bi1/2)1−xBaxTiO3, x

A new class of active fiber devices based on piezoelectric coated optical fibers is currently being developed. The piezoelectric coating is used to produce acoustic waves within the optical fiber and these acoustic waves interfere with optical signals passing through the fiber waveguide. Optical phase modulation devices based on piezoelectric coated fibers have been demonstrated and the behavior of these devices will be reviewed. A second type of active optical fiber device has been fabricated by integratin

Electric-field-induced phase transitions have been evidenced by macroscopic strain measurements at temperatures between 25 degrees C and 100 degrees C in 001-poled (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) [(PMN-xPT);x=0.25,0.305,0.31] and (1-x)Pb(Zn1/3Nb2/3)O ...

The properties of ferroelectric materials, such as lead zirconate titanate (PZT), are heavily influenced by the interaction of defects with domain walls. These defects are either intrinsic or are induced by the addition of dopants. We study here PbTiO3 (th ...

We report on the ferroelectric domain evolution as a function of the depth of the surface of 100 mum thick bulk Pb(Zr,Ti)O-3 (PZT) doped with 2% Nb. Ferroelectric domain imaging (FDI) was performed by piezoelectric detection assisted by atomic force microscopy (AFM). The depth evolution, of the polarization orientation was obtained by repeated surface chemical etching followed by FDI. It was observed that backswitching mainly occurred close to 90degrees domain and grain boundaries. The depth of these domain

The effect of Nb on the hysteresis parameters of sol-gel Pb-1.1-x/2(Zr0.53Ti0.47)(1-x)NbxO3 (x = 0.0 - 0.05, increments of 0.01) thin films is reported. Two sets of (111) textured films, rapid annealed at 600 and 650 degrees C, were studied. The degree of texture and grain size as a function of Nb was analogous for the two sets. Surface coverage by a pyrochlore phase increased with Nb addition, however its quantity and distribution was determined by the annealing temperature, being less for the 650 degrees

Nava Setter

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Influence of flexoelectric coupling on domain patterns in ferroelectrics

Sol-gel derived Pb(Sc0.5Nb0.5)O-3 thin films: Processing and dielctric properties

Post-deposition control of ferroelastic stripe domains and internal electric field by thermal treatment

Identification of Passive Layer in Ferroelectric Thin-Films from Their Switching Parameters

Direct piezoelectric effect in relaxor-ferroelectric single crystals

Study and control of the conductivity of Nb-doped Bi4Ti3O12 for high temperature piezoelectric applications

Processing and properties of screen-printed lead zirconate titanate piezoelectric thick films on electroded silicon

Pb(Mg1/3Nb2/3)O-3 and (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) relaxor ferroelectric thick films: Processing and electrical characterization

Piezoelectric micromachined ultrasonic transducers based on PZT thin films

Dielectric breakdown in (Pb,La)(Zr,Ti)O-3 ferroelectric thin films with Pt and oxide electrodes

Cold-Field Switching in PVDF-TrFE Ferroelectric Polymer Nanomesas

Effects of yttrium and sodium addition on preparation and humidity sensitivity of porous apatite ceramics

Strain Engineering of Electrical Conductivity in Epitaxial Thin Ba0.7Sr0.3TiO3 Film Heterostructures

Controlled stripes of ultrafine ferroelectric domains

Structural complexity of (Na0.5Bi0.5)TiO3-BaTiO3 as revealed by Raman spectroscopy

Piezoelectric coatings for active optical fiber devices

Electric-field-, temperature-, and stress-induced phase transitions in relaxor ferroelectric single crystals

Defect ordering and defect-domain-wall interactions in PbTiO3: A first-principles study

Three-dimensional ferroelectric domain imaging of bulk Pb(Zr,Ti)O-3 by atomic force microscopy

Effect of Nb doping on the hysteresis parameters of sol-gel derived Pb-1.1-x/2(Zr0.53TiO0.47)(1-x)NbxO3 thin films