Publications de Dragan Damjanovic

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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 ...

Pyrochlore free 0.9Pb(Mg1/3Nb2/3)O-3-0.1PbTiO(3) thin films were prepared from alkoxide-based solution precursors. Preferential (111) crystallographic orientation was obtained on TiO2/Pt/TiO2/SiO2/Si substrates by spin coating. Dielectric, electrostrictive, and piezoelectric properties of the films were characterized in detail. Films show relaxor-like behavior, but with dielectric permittivity which is low (around 4300 at peak and at 340 Hz with E-ac=1.6x10(6) V/m) compared to bulk ceramics and single cryst

Lead oxide based ferroelectrics, represented by lead zirconate titanate (Pb(Zr,Ti)O-3) or PZT) are the most widely used materials for piezoelectric actuators, sensors and transducers due to their excellent piezoelectric properties. Considering lead toxicity, there is interest in developing piezoelectric materials that are biocompatible and environmentally friendlier. The low density of non-lead based materials can also be an advantage in transducers for underwater and medical imaging due to expected lower a

Piezoelectric response nonlinearity is approached using the Preisach description of hysteretic systems as collection of distributed bistable units. The Preisach model and its recent physical interpretation in terms of moving domain wall in a stochastically described pinning field are reviewed. It is shown that such an approach can effectively render not only the piezoelectric coefficient field dependences but also the field-response hysteresis, especially in the well-known case of linear piezoelectric field

The converse piezoelectric response of Pb(ZrxTi1−x)O3 ceramics is investigated as a function of material composition. The effects of the crystallographic phase and different dopants on piezoelectric nonlinearity are separately examined. For a linear depend ...

The electrostrictive effect, which induces strain in ferroelectric ceramics, offers distinct advantages over its piezoelectric counterpart for high-precision actuator applications, including anhysteretic behavior even at high frequencies, rapid reaction ti ...

The transverse piezoelectric coefficient (d(31)(star)) has been calculated for tetragonal barium titanate (BT) and lead titanate (PT) cut along nonpolar axes, over a range of temperatures, using the phenomenological Landau-Ginzburg-Devonshire theory. It is ...

Pinning of the ferroelastic-ferroelectric domain walls on randomly distributed defects in ferroelectric ceramics leads to a field dependence of the piezoelectric coefficient that is analogous to the Rayleigh law for magnetic susceptibility. It is shown in this paper that the piezoelectric coefficient of a lead zirconate titanate ferroelastic-ferroelectric system depends linearly on the logarithm of the frequency of the field. Both the reversible and irreversible components of the piezoelectric coefficient a

The nature of the "forbidden" local- and long-range polar order in nominally nonpolar paraelectric phases of ferroelectric materials has been an open question since the discovery of ferroelectricity in oxide perovskites (ABO3). A currently considered model ...

The piezoelectric properties of SrBi4Ti4O15 and Bi4Ti2.95Nb0.04O12 have been compared as a function of applied ac stress. Evidence of domain-wall motion was observed in Bi4Ti2.95Nb0.04O12 but not in SrBi4Ti4O15. Examination of SrBi4Ti4O15 using transmission electron microscopy revealed that the material had undergone an orthorhombic-orthorhombic, paraelectric-ferroelectric, phase transition in which no piezoelectrically active, non-180 degrees, domain walls could be created. However, for the orthorhombic-mo

Lead-free, potassium sodium niobate piezoelectric ceramics substituted with lithium (K0.5-x/2,Na0.5-x/2,Li-x)NbO3 or lithium and tantalum (K0.5-x/2,Na0.5-x/2,Li-x)(Nb1-y,Ta-y)O-3 have been synthesized by traditional solid state sintering. The compositions ...

The correlation between structure and electrical properties of lead-free (1-x)(Bi1/2Na1/2)TiO3-xBaTiO(3) (BNT-100xBT) polycrystalline piezoceramics was investigated systematically by in situ synchrotron diffraction technique, combined with electrical property characterization. It was found that the morphotropic phase boundary (MPB) between a rhombohedral and a tetragonal phase evolved into a morphotropic phase region with electric field. In the unpoled material, the MPB was positioned at the transition from

The paper discusses different possibilities for controlling piezoelectric properties of ferroelectric materials and devices. The piezoelectric properties engineering can be made on different scales. Tuning of the piezoelectric response by controlling contributions from domain walls displacement is used to illustrate engineering on nanometer scale. Texture control in ferroelectric films and grain size control is discussed as an example of property control on micrometer scale. Finally, engineering on macrosco

The effect of boundary conditions (e.g., type of metal contacts) and sample geometry (e.g., sample aspect ratio) on measurements of direct longitudinal d(33) coefficient in piezoelectric ceramics is studied by direct quasistatic method. We show that at small aspect ratio (thickness/lateral dimension

Pb(Mg1/3Nb2/3)O-3 thin films were prepared from modified alkoxide solution precursors and their dielectric and electromechanical characteristics were investigated. Preparation of the films is very sensitive to processing parameters. The influence of different seeding layers on the microstructures is discussed. Films show relaxer-like behavior, but with dielectric permittivity which is low (4500 at peak) compared to bulk ceramics and single crystals. Large electric de bias fields (up to 120 kV/cm) can be app

A centrosymmetric stress cannot induce a polar response in centric materials; piezoelectricity is, for example, possible only in non-centrosymmetric structures. An exception is meta-materials with shape asymmetry, which may be polarized by stress even when ...

After twenty years of partly quiet and ten years of partly enthusiastic research into lead-free piezoceramics there are now clear prospects for transfer into applications in some areas. This mimics prior research into eliminating lead from other technologi ...

In this work, we present the development of a 3D lattice-type model at microscale based upon the Voronoi-cell representation of material microstructure. This model can capture the coupling between mechanic and electric fields with non-linear constitutive b ...

BaTiO3 appears in cubic and hexagonal variants, both of which are centrosymmetric. Samples of cubic BaTiO3 are known to exhibit breaking of the centric symmetry locally and globally. It has been proposed that the local symmetry breaking originates in polar ...

The solid solution of (x)Ba0.7Ca0.3TiO3-(1-x)BaZr0.2Ti0.8O3 is known to exhibit high piezoelectric constants. Discrepancies in the reported phase transitions and structure around room temperature, however, have complicated the understanding of the enhanced ...

Dragan Damjanovic

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

Dielectric and electromechanical properties of ferroelectric-relaxor 0.9 Pb(Mg1/3Nb2/3)O-3-0.1PbTiO(3) thin films

Lead free piezoelectric materials

Preisach modeling of piezoelectric nonlinearity in ferroelectric ceramics

Subcoercive cyclic electrical loading of lead zirconate titanate ceramics I: nonlinearities and losses in the converse piezoelectric effect

Ultrahigh Electrostrictive Effect in Lead-Free Ferroelectric Ceramics Via Texture Engineering

Correlation between dielectric anisotropy and positive or zero transverse piezoelectric coefficients in perovskite ferroelectric single crystals

Logarithmic frequency dependence of the piezoelectric effect due to pinning of ferroelectric-ferroelastic domain walls

Atomic scale symmetry and polar nanoclusters in the paraelectric phase of ferroelectric materials

Crystal structure and domain-wall contributions to the piezoelectric properties of strontium bismuth titanate ceramics

Piezoelectric properties of Li- and Ta-modified (K0.5Na0.5)NbO3 ceramics

Evolving morphotropic phase boundary in lead-free (Bi[sub 1/2]Na[sub 1/2])TiO[sub 3]–BaTiO[sub 3] piezoceramics

Engineering of piezoelectric properties in ferroelectric ceramics and thin films

The effect of boundary conditions and sample aspect ratio on apparent d(33) piezoelectric coefficient determined by direct quasistatic method

Relaxor Pb(Mg1/3Nb2/3)O-3 thin films and their electromechanical properties

Breaking of macroscopic centric symmetry in paraelectric phases of ferroelectric materials and implications for flexoelectricity

Transferring lead-free piezoelectric ceramics into application

Multi-scale model for coupled piezoelectric-inelastic behavior

Symmetry breaking in hexagonal and cubic polymorphs of BaTiO3

Structure and phase transitions in 0.5(Ba0.7Ca0.3TiO3)-0.5(BaZr0.2Ti0.8O3) from −100°C to 150°C