Publications by Alexander Tagantsev

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Control of domain and domain wall configurations in antiferroelectrics is a necessary step towards practical use of new functionalities based on polar domain wall structures. Here we propose and demonstrate a domain engineering scheme that provides an anti ...

The ferroelectric transition of bulk strontium titanate is suppressed by a combination of two effects: (1) the structural changes produced by the antiferrodistortive transition at T-a =105 K and (2) the quantum fluctuations. The structural changes are strongly perturbed within antiphase domain boundaries , and this in such a manner that a ferroelectric transition should occur in boundaries containing the tetragonal c-axis at T-c similar to 35 to 40 K. This provides a possible explanation for a number of ano

Stress-induced changes in the imprint and switching behavior of (111)-oriented Pb(Zr,Ti)O-3 (PZT)-based capacitors have been studied using piezoresponse force microscopy. Visualization of polarization distribution and d(33)-loop measurements in individual 1x1.5-mum(2) capacitors before and after stress application, generated by substrate bending, provided direct experimental evidence of stress-induced switching. Mechanical stress caused elastic switching in capacitors with the direction of the resulting pol

The effect of 1 MeV ion implantation on leakage conduction, dielectric and ferroelectric properties of the Pt/Pb(ZrxTi1-x)(2)O-3/Pt capacitors is studied for a wide range of implantation doses (10(10)-10(16) cm(-2)). It is shown that the implantation of Pt+, with an implant and vacancy profile peaking at the bottom interface and a dose within the range of 10(13)-10(16) cm(-2), provokes a strong suppression of the leakage conduction and ferroelectric hysteresis. In addition, ion implantation results in a dec

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

We present a highly reflective, sub-wavelength-thick membrane resonator featuring high mechanical quality factor and discuss its applicability for cavity optomechanics. The 88.5 nm thin stoichiometric silicon-nitride membrane, designed and fabricated to co ...

(001)-epitaxial (Ba0.5Sr0.5)TiO3 (BST) thin films with different magnitudes of compressive strain were fabricated on SrRuO3/SrTiO3 substrates by pulsed laser deposition, and their electro-optic (EO) properties were characterized by modulation ellipsometry ...

The temperature behavior of the generation of the second acoustic harmonics induced by an electric field during the transition of a crystal to the ferroelectric state has been considered based on the thermodynamic approach in the framework of the Landau model. It has been shown that the appearance of the contribution to polarization quadratic in the electric field leads to a change in the sign of the second acoustic harmonics and a change in its magnitude as compared to the paraphase. The results of the cal

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

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

We analyze a cavity optomechanical setup, in which the position of an oscillator modulates the internal optical loss. We show that, in contrast to systems with a fixed internal loss, in such a setup, quantum-limited position measurements can be performed a ...

Leakage conduction of (Pb, La)(Zr, Ti)O-3 (PLZT) films grown on Pt bottom electrode, with Pt and Pt/SrRuO3 (Pt/SRO) top electrodes is studied. It is found that the conduction behavior of the ferroelectric capacitors strongly varies depending on the degree of interdiffusion from the electrode into the ferroelectric material. If the diffusion is limited, the conduction properties of the Pt/SRO/PLZT/Pt capacitor are similar to that of the conventional Pt/PLZT/Pt system. For the opposite case of excessive inter

The dielectric response of ferroelectric-dielectric composites is theoretically addressed. Dielectric permittivity, tunability (relative change of the permittivity driven by dc electric field), and loss tangent are evaluated for various composite models. T ...

Fatigued state of the Pt-PZT-Pt system is studied by means of low-temperature conduction measurements. It is shown that the conduction in the temperature interval of 100-140 degrees K is determined by the cold field emission of electrons (tunneling conduction mechanism). The Fowler-Nordheim equation describes well the observed current-voltage relations for reasonable values of the system parameters. The conduction measurements in this regime show that the strong fatigue of the switching polarization provoke

Direct evidence for freezing in two relaxer ferroelectrics, PbMg1/3Nb2/3O3 and PbSc1/2Ta1/2O3, at a certain temperature T-f not equal 0K was obtained from the temperature dependence of the maximum relaxation time, tau(max), It was shown that tau(max)(T) follows the Vogel-Fulcher (VF) law, and tends toward infinity as temperature approaches T-f. The freezing temperature T-f derived from tau(max)(T) coincides with the value of T-f obtained from the fit of frequency, omega, dependence of the temperature, T-max

A silicone-based one-transistor nonvolatile memory cell has been implemented by integration of a ferroelectric polymer gate on a standard n- type metal oxide semiconductor field effect transistor. The polarization reversal in the gate results in a stable a ...

Systems with a ferroelectric to paraelectric transition in the vicinity of room temperature are useful for devices. Adjusting the ferroelectric transition temperature (T-c) is traditionally accomplished by chemical substitution - as in BaxSr1-xTiO3, the material widely investigated for microwave devices in which the dielectric constant (epsilon(r)) at GHz frequencies is tuned by applying a quasi-static electric field(1,2). Heterogeneity associated with chemical substitution in such films, however, can broad

A zero-field spontaneous relaxor-ferroelectric transition is reported in Pb(Sc0.5Ta0.5)O3 (PST). This behavior is different from that of other relaxors, where such transitions occur only under the field. A highly disordered PST that has the wide relaxation spectrum typical of relaxors is shown to transform spontaneously into a macroscopic ferroelectric state. Introduction of defects (lead vacancies) into the material impedes the transition resulting in the usual relaxor behavior. Dielectric properties of PS

The switching, fatigue and rejuvenation phenomena of ferroelectric PZT thin films with differently processed electrode-PZT interfaces and of different thicknesses have been investigated. The ferroelectric contribution to the switching parameters has been isolated from the leakage current contribution, thus allowing the identification of several salient features of the above phenomena. Incorporating our present results with already established properties of PZT thin films, a set of characteristic features of

We report results on electric DC-field induced and self induced recovery of the switched remanent polarisation (P-r(s)) in fatigued ferroelectric thin films. The field induced recovery is characterised by a strong asymmetry and depends on the ratio between the fatiguing and DC-field magnitudes. It is also dependent on the period of application of the DC-field. The self recovery effect occurs on further cycling beyond the fatigued state. It is dependent on the fatiguing field magnitude and also, if the cycli

Alexander Tagantsev

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Electric field control of antiferroelectric domain pattern

Low-T ferroelectricity in antiphase domain boundaries of SrTiO3

Mechanical stress effect on imprint behavior of integrated ferroelectric capacitors

Pt-ion-implantation-induced suppression of leakage conduction in Pt/Pb(ZrxTi1-x)O-3/Pt capacitors

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

Phononically shielded photonic-crystal mirror membranes for cavity quantum optomechanics

Large impact of strain on the electro-optic effect in (Ba, Sr)TiO3 thin films: Experiment and theoretical comparison

Thermodynamic description of generation of the second acoustic harmonics induced by an electric field in ferroelectrics

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

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

Quantum-Limited Measurements Using an Optical Cavity with Modulated Intrinsic Loss

Control of leakage conduction of high-fatigue-endurance (Pb, La)(Zr, Ti)O-3 film ferroelectric capacitors with Pt/SrRuO3 electrodes

Ferroelectric-dielectric tunable composites

Tunneling conduction in virgin and fatigued states of PZT films

Direct evidence for Vogel-Fulcher freezing in relaxor ferroelectrics

Retention in nonvolatile silicon transistors with an organic ferroelectric gate

Room-temperature ferroelectricity in strained SrTiO3

The Spontaneous Relaxor-Ferroelectric Transition of Pb(Sc0.5ta0.5)O3

Fatigue, Rejuvenation and Self-Restoring in Ferroelectric Thin-Films

DC-voltage and cycling induced recovery of switched polarisation in fatigued ferroelectric thin films