Publications de Dragan Damjanovic

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The ac field dependence of dielectric and piezoelectric response of sol-gel derived Pb(Zr,Ti)O(3)thin films is presented. The nonlinear response of dielectric polarisation and piezoelectrically induced strain at sub-switching fields was studied in terms of amplitude and phase angle of first and third harmonic. The experimental results have shown that a description by a classical polynomial approach cannot account for many features of observed behavior. However, a model based on the pinning of domain walls o

Nonlinear dielectric response of soft and hard PZT is experimentally studied at subswitching conditions. The correlations between defect disordering and parameters of nonlinear dielectric response and hysteresis are demonstrated and discussed. (c) 2005 Els ...

The dynamic dielectric nonlinearity of barium strontium titanate (Ba1-x, Sr-x) TiO3 ceramics is investigated in their paraelectric phase. With the goal to contribute to the identification of the mechanisms that govern the dielectric nonlinearity in this fa ...

The evolution of switching polarization (P-r(s)) suppression, in Pb(Zr,Ti)O-3 films, induced by two different electric treatments is addressed in terms of the nonlinear dielectric response. The ac electric field dependence of dielectric permittivity was collected at different fatigue states and the Rayleigh law was used to interpret the fatigue dependence of the nonlinear response. This approach has enabled us to distinguish between two fatigue stares induced by the different electric treatments.

The most significant advance in this field in the past year has been the demonstration that single-crystal langasite, La3Ga5SiO14, can be used, at least at high frequencies, at temperatures up to 1000 degrees C. New evidence suggests that domain-wall contributions to the piezoelectric response of bismuth-titanate-based high temperature ferroelectric ceramics may be controlled using suitably chosen dopants. Modified bismuth titanate compositions are interesting for sensor applications in the medium temperatu

Research on lead-free piezoceramics has dramatically increased over the last years due to stringent legislation demanding to phase out current lead- containing piezoceramics. The use of electrostrictive materials for electric-field induced strain has been ...

The Preisach approach is applied to model ferroelectric pinched (or constricted) loops. Starting from the existence of distributed switchable dipolar defects in the material and a corresponding distribution function, an analytical expression for the resulting ferroelectric loop is obtained. The corresponding hysteresis shape is indeed showing a clear pinching. Considerations about defect distribution expression and ways to characterize it from the loop are also made. It is finally suggested that such a desc

The piezoelectric properties of rhombohedral relaxor-ferroelectric compositions close to morphotropic phase boundary have been studied as a function of temperature. As they exhibit, upon heating, a rhombohedral to tetragonal phase transition the piezoelectric behavior changed with temperature. Large piezoelectric (d(33)) and coupling (k(33)) coefficients of 0.91 Pb(Zn1/3Nb2/3)O-3-0.09PbTiO(3) single crystals drop to usual ceramic values after crossing the transition. Intrinsic and reversible contributions t

The direct piezoelectric effect in fine and coarse grain barium titanate ceramics is examined as a function of the external alternating and static pressure. It is found that domain wall vibrations contribute to the piezoelectric effect in both types of ceramics, but this contribution is smaller in the fine grain material. The external static pressure reduces domain wall contributions in the coarse grain samples and has little effect on the properties of the fine grain material. The results are consistent wi

This paper discusses the mechanisms that can contribute to the enhanced longitudinal piezoelectric effect along nonpolar directions in perovskite crystals, such as BaTiO3, PbTiO3, KNbO3, Pb(Mg1/3Nb2/3)O-3-PbTiO3 and Pb(Zn1/2Nb2/3)O-3-PbTiO3. Piezoelectric ...

The reasons for the lower piezoelectric properties in the most studied lead-free piezoelectrics, modified (K,Na)NbO3 and (Bi0.5Na0.5)TiO3, are discussed. Contributions from domain wall motion and properties at the morphotropic phase boundary are considered ...

Nanoscale and mesoscopic disorder and associated local hysteretic responses underpin the unique properties of spin and cluster glasses, phase-separated oxides, polycrystalline ferroelectrics, and ferromagnets alike. Despite the rich history of the field, t ...

Using Landau-Ginzburg-Devonshire theory and tetragonal BaTiO3 as an example, this letter demonstrates that strong electric bias fields applied antiparallel to spontaneous polarization may lead to a large enhancement of piezoelectric properties in monodomain perovskite crystals with multiple phase transitions. At temperatures close to tetragonal-orthorhombic phase transition, the largest enhancement is approximately along the [111] axis. The enhancement is due to the field induced dielectric softening of the

Charged domain walls in proper ferroelectrics were shown recently to possess metallic-like conductivity. Unlike conventional heterointerfaces, these walls can be displaced inside a dielectric by an electric field, which is of interest for future electronic ...

Bismuth ferrite (BiFeO3), a perovskite material, rich in properties and with wide functionality, has had a marked impact on the field of multiferroics, as evidenced by the hundreds of articles published annually over the past 10 years. Studies from the ver ...

The results of recent studies of domain walls and their interaction with defects in BaTiO3, Pb(Zr, Ti)O-3, and BiFeO3 are discussed. The studies reveal why donor- and acceptor-doped Pb(Zr, Ti)O-3 behave differently, what is the role of stationary charged d ...

Using a serial bilayer model we show that heterogeneous ferroelectric systems may exhibit substantial Maxwell-Wagner piezoelectric relaxation. The relaxation has its origin in the coupling of the dielectric and piezoelectric properties. The model predicts both retardation (positive phase angle and counterclockwise charge-pressure hysteresis) and relaxation (negative phase angle and clockwise charge-pressure hysteresis) of the longitudinal direct piezoelectric coefficient. The theoretical results are confirm

Dragan Damjanovic

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Nonlinear contributions to dielectric and piezoelectric properties in lead zirconate titanate thin films

The nonlinearity and subswitching hysteresis in hard and soft PZT

Nonlinear dynamics of polar regions in paraelectric phase of (Ba1-x,Srx)TiO3 ceramics

Fatigue and nonlinear dielectric response in sol-gel derived lead zirconate titanate thin films

Materials for high temperature piezoelectric transducers

Rotator and extender ferroelectrics: Importance of the shear coefficient to the piezoelectric properties of domain-engineered crystals and ceramics

High-Strain Lead-free Antiferroelectric Electrostrictors

Preisach modeling of ferroelectric pinched loops

Temperature dependence of piezoelectric properties for relaxor-ferroelectric solid solutions undergoing a rhombohedral to tetragonal phase transition

Dependence of the direct piezoelectric effect in coarse and fine grain barium titanate ceramics on dynamic and static pressure

Piezoelectric anisotropy: Enhanced piezoelectric response along nonpolar directions in perovskite crystals

What Can Be Expected From Lead-Free Piezoelectric Materials?

Collective dynamics underpins Rayleigh behavior in disordered polycrystalline ferroelectrics

Large enhancement of the piezoelectric response in perovskite crystals by electric bias field antiparallel to polarization

Formation of charged ferroelectric domain walls with controlled periodicity

BiFeO3 Ceramics: Processing, Electrical, and Electromechanical Properties

Domain walls and defects in ferroelectric materials

Erratum: Evidence for dielectric aging due to progressive 180° domain wall pinning in polydomain Pb(Zr0.45Ti0.55)O3 thin films [Phys. Rev. B 79, 054104 (2009)]

Piezoelectric nonlinearity due to motion of 180 degrees domain walls in ferroelectric materials at subcoercive fields: A dynamic poling model

Maxwell-Wagner piezoelectric relaxation in ferroelectric heterostructures