Publications by Dragan Damjanovic

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Limited reliability of ferroelectric-based actuators restricts their use in high-performance applications, where stress-induced cracking of ferroelectric ceramics often leads to fatal failure. The main limiting factors are the relatively small fracture toughness and the brittle nature of ferroelectrics. However, ferroelectrics naturally exhibit fracture toughening (so called ferroelastic toughening) due to stress induced reorientation of non-180 degrees domains that inhibits crack propagation. Here we prese

In this study (0-3) P(VDF-TrFE)/BaTiO3 composites containing up to 60 vol% of ceramic phase were prepared by solvent casting or compression molding. Their thermomechanical, dielectric, and piezoelectric properties were investigated, and discussed in the li ...

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle ...

A modified processing method for lead nickel niobate-lead zirconate titanate (Pb(Ni1/3Nb2/3)O-3-Pb(Zr,Ti)O-3, PNN-PZT) solid solutions is presented. This method is based on the high-temperature synthesis of a precursor that contains all the B-site cations (Ti, Zr, Ni, and Nb). This synthesis yields a diphasic mixture that contains a ZrTiO4-like phase and a rutile-like phase. Both phases exhibit a cationic valence of 4; thus, it is concluded that the mixing of Ni and Nb cations is adequate for the preparatio

The (1-x)Pb(Sc1/2Nb1/2)O-3-xPbTiO(3)(x=0.4, PSNT(60/40)) thin films near the morphotropic phase boundary(MPB) composition were successfully deposited via sol-gel method. Taking the strict controls of processing factors such as the stable and homogeneous precursor solutions, conditions of heat treatment and suitable substrates, it was possible to obtain the pyrochlore-free PSNT(60/40) thin films. The effect of substrate on the microstructure and crystallographic orientation is shown. Dielectric behaviors of

Thin films of neodymium-modified bismuth titanate Bi3.44Nd0.56Ti3O12 (BNT) were grown on Pt/TiO2/SiO2/Si substrates using chemical solution deposition method. The capacitors made by applying top Au electrodes on BNT films showed significantly improved values of the remanent polarization as compared to that using bismuth titanate Bi4Ti3O12 (BT) films. The 2P(r) value for the BNT capacitors was determined to be equal to 38 muC/cm(2) at an applied voltage of 24 V, whereas, for Bi4Ti3O12 ( BT) capacitors a valu

[001]-Oriented barium titanate (BaTiO3) ceramics were prepared by templated grain growth using [001]-oriented plate-like template BaTiO3 particles, synthesized via the molten salt method. Platelets synthesized in a 2-step or 3-step molten salt were used in ...

BiFeO3 is a ferroelectric with a Curie temperature of 830 C-degrees, however, its piezoelectric performance at high temperature remains unclear. The current work reveals a disappearance/recovery of piezoelectricity in BiFeO3 at elevated temperature and upo ...

The stability of electrically induced long-range ferroelectric order in a relaxor 0.94(Bi1/2Na1/2) TiO3-0.06BaTiO(3) ceramic material has been investigated by temperature-dependent X-ray diffraction and electrical property measurements. The depolarization ...

In this paper the preparation and characterization of the ceramic material (K0.5Na0.5)NbO3 (KNN) has been studied. Although conventional processing of KNN is often reported to result in sintered bodies lacking sufficient density, samples produced in this w ...

A phase diagram based on dielectric-permittivity-versus-temperature measurements and high-temperature X-ray diffractometry was proposed for 0.4Pb(Ni-1/3,Nb-1/3) O-3-xPbZrO(3)-(0.6-x)PbTiO3, (0.2 less than or equal to x less than or equal to 0.32) relaxor-ferroelectric solid solution, and a morphotropic phase boundary that sharply bends toward zirconium-rich compositions was found. A spontaneous normal-to-relaxer ferroelectric transition was also observed when heating was performed for all the compositions t

The paper describes processing and dielectric properties of 0.65Pb(Mn1/3Nb2/3)O-3-0.35PbTiO(3) films deposited on alumina and silicon substrates by screen-printing. Ink development and problems associated with adhesion of electrodes to substrate are discus ...

Micron- and submicron-sized barium titanate (BaTiO3) particles, untreated and surface modified with aminopropyl triethoxy silane, were incorporated in poly(vinylidene fluoride-trifluoroethylene) to fabricate composites with up to 60 vol% of ceramic phase. ...

The ac field dependence of dielectric response of sol-gel derived Pb(Zr, Ti)O-3 thin films is presented. The analysis of amplitude and phase angle of first and third harmonic of the polarization at subswitching fields shows that a description of the dielectric nonlinearity by the classical polynomial approximation is inadequate. A qualitatively better description of many features of the experimental data is obtained using the Rayleigh relationship, indicating that the nonlinear behavior is associated with t

A phenomenological approach is proposed describing both nonlinearity and frequency dispersion in dielectric and piezoelectric properties of lead zirconate titanate, Pb(Zr,Ti)O-3 (PZT), thin films and ceramics. The approach couples the frequency dependent r ...

Pyrochlore free Pb(Mg1/3Nb2/3)O-3 (PMN) thin films were prepared from mixed-metal precursors solutions using the sol-gel process. Lead acetate [Pb(CH3COO)(2)], magnesium acetate [Mg(CH3COO)(2)] and niobium ethoxide [Nb(C2H5O)5] were used as starting materials, while 2-isopropoxy-ethanol was chosen as solvent. The reactivity of the precursors was investigated in order to understand and control the process and thus to prevent the contamination of the PMN with the pyrochlore phase. The solution was spin-coated

A study of the complex permittivity in bismuth titanate was conducted to reveal the nature of an anomaly in the real part of the permittivity, which occurs below the Curie temperature. This anomaly is frequency dependent and is caused by a combination of two relaxation phenomena that appear in the imaginary part of the permittivity. One of the relaxations showed classic characteristics of an ion-jump process. Niobium doping suppressed this relaxation and eliminated the nonferroelectric anomaly in permittivi

While in the paralectric phase of ferroelectrics, and in centrosymmetric materials in general, the dielectric tunability is symmetrical for positive and negative electric bias fields, in noncentrosymmetric materials this is not the case. By using the therm ...

Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics are reviewed with the aim of providing an insight into different processes which may affect the behaviour of ferroelectric devices, such as ferroelectric memories and micro-electro-mechanical systems. Taking into consideration recent advances in this field, topics such as polarization switching, polarization fatigue, effects of defects, depletion layers, and depolarization fields on hysteresis loop behaviour, and

Using recently published experimental data we calculated the piezoelectric response of rhombohedral 0.67Pb(Mg1/3Nb2/3)O-3-0.33PbTiO(3) monodomain single crystals along arbitrary directions. The calculations indicate that the value of the longitudinal piezoelectric coefficient along the [001] axis of the pseudocubic system ([111] axis of the rhombohedral system) of a monodomain crystal is close to the value determined experimentally along the same direction of a multidomain crystal with a so-called "engineer

Dragan Damjanovic

Chat with Graph Search

Phase field simulations of ferroelastic toughening: The influence of phase boundaries and domain structures

The effect of processing conditions on the morphology, thermomechanical, dielectric, and piezoelectric properties of P(VDF-TrFE)/BaTiO3 composites

Induced giant piezoelectricity in centrosymmetric oxides

Synthesis of lead nickel niobate-lead zirconate titanate solid solutions by a B-site precursor method

Preparation and dielectric properties of Pb(Sc1/2Nb1/2)O-3-PbTiO3 thin films near MPB compositions

Properties of chemical solution deposited polycrystalline neodymium-modified Bi4Ti3O12

Textured BaTiO3 by templated grain growth and electrophoretic deposition

Piezoelectric Properties of BiFeO3 Exposed to High Temperatures

Two-stage processes of electrically induced-ferroelectric to relaxor transition in 0.94(Bi1/2Na1/2)TiO3-0.06BaTiO3

Preparation and Characterization of (K0.5, Na0.5)NbO3 Ceramics

Phase diagram for the 0.4Pb(Ni-1/3,Nb-1/3)O-3-0.6Pb(Zr,Ti)O-3 solid solution in the vicinity of a morphotropic phase boundary

Development of relaxor ferroelectric materials for screen-printing on alumina and silicon substrates

Effect of silane coupling agent on the morphology, structure, and properties of poly(vinylidene fluoride-trifluoroethylene)/BaTiO3 composites

Domain wall pinning contribution to the nonlinear dielectric permittivity in Pb(Zr, Ti)O-3 thin films

Toward a unified description of nonlinearity and frequency dispersion of piezoelectric and dielectric responses in Pb(Zr,Ti)O-3

New sol-gel route for processing of PMN thin films

Niobium doping and dielectric anomalies in bismuth titanate

Extension of the dielectric tunability range in ferroelectric materials by electric bias field antiparallel to polarization

Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics

Monodomain versus polydomain piezoelectric response of 0.67Pb(Mg1/3Nb2/3)O-3-0.33PbTiO(3) single crystals along nonpolar directions