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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

The self-polarization effect is investigated in Pb(Zr,Ti)O-3 (PZT) thin films deposited by sol-gel and magnetron sputtering techniques. The effective piezoelectric coefficient of as-grown films, which is proportional to their initial polarization (self-polarization), is measured by a sensitive interferometric technique as a function of the annealing temperature, PZT composition, film thickness and bottom electrode material. The results indicate that the films are self-polarized by an internal bias field upo

We present a far infrared gas spectrometer which uses a thin film pyroelectric detector integrated on silicon. The detector is in-house fabricated and consists of 1 x 50 elements of sol-gel deposited, zirconium rich lead titanate (PZT) which are suspended on a submicron membrane for thermal insulation. The detector shows a detectivity of 16 mu A/W and is mounted into a Oriel monochromator fitted with gratings for the 3-5 mu m and the 8-12 mu m range, respectively. The infrared radiation is emitted by a hot

The electronic structure of hydrated SrTiO3 (001) surfaces is investigated using density-functional models. It is shown that adsorbed water molecules give rise to unoccupied electron states similar in localization and shape to wet-electron states recently reported for other oxide-water interfaces, and believed to serve as a preferred path for transfer of conduction electrons to the surface water molecules. Additionally, we found that chemisorbed water and hydrogen have donor levels in the band gap, and that

The switching kinetics in ferroelectric thin films has been intensively studied during the past decade. It is widely accepted that this kinetics is basically governed by the dynamics of domain coalescence (the Kolmogorov-Avrami-Ishibashi model). This conclusion is mainly supported by fitting the time dependence of the switching currents to that predicted by this model, the fit being typically performed in a 1-2 decade interval of time. The present paper reports on a study of the switching kinetics in modifi

Combination of ferroelectric layers and semiconductor heterostructures with 2D electron gas may lead to a number of new applications from high-mobility field effect transistors with ferroelectric gates to quantum dots patterned with polarization domains at sub-micron scale. One of the fundamental obstacles impeding implementation of such devices is associated with the unfavorable relation between the dielectric constants of the classical oxide ferroelectrics and semiconductors. In the present work we demons

The region-by-region polarization switching in ferroelectric Pb(Zr,Ti)O-3 thin films sandwiched between Pt electrodes has been directly observed using piezoelectric scanning probe microscopy. A resolution improved by one order-of-magnitude compared to the ...

Ferroelectric capacitive devices for memory and MEMS applications require patterned ferroelectric thin films with high anisotropic etched features. In this paper, physical and chemical parameters during etching of Pb(Zr0.53Ti0.47)O-3 (PZT) by a dual frequency ECR/RF reactor have been investigated. The removal characteristics of blanket films and films with a patterned mask were investigated as a function of gas chemistry (Ar, halogen gases), substrate bias RF power and working pressure (from 5 x 10(-4) Pa t

Understanding of polarization reversal mechanisms in ferroelectric films is essential for evaluation and prediction of the properties of ferroelectric devices including nonvolatile memories. The widely accepted approach based on the domain wall motion kinetics describes correctly switching in single crystals but does not work properly for thin ferroelectric films used for memory applications. Recently an alternative approach based the on statistics of nucleation of the reversed polarization domain has been

Polarization reversal in BiFeO3 (BFO) thin films in a parallel-plate capacitor configuration has been explored using piezo-force microscopy (PFM). Through-electrode mapping of the local piezoresponse allows for direct observation of the domain growth, whic ...

Transient photocurrents are investigated in ferroelectric lead zirconate titanate (PZT) films illuminated by laser pulses in the spectral range of 340-380 nm. At low electric fields, the photocurrent is sensitive to the ferroelectric polarization state and changes sign upon the polarization switching. At higher fields, the polarization-independent current proportional to the applied electric field is dominant. The spectral dependence of polarization-dependent current is controlled by the excitation of charg

A PZT, Pb(Zr,Ti)O-3 (40:60), ferroelectric layer has been successfully deposited onto a Al0.3Ga0.7N/GaN heterostructure with a 2DEG, two dimensional electron gas. Due to the chemical and temperature stability of AlGaN/GaN it was possible to implement the c ...

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 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

Relaxor Pb(Sc-12/Ta-1/2)O-3 (PST) thin films have been prepared using mixed alkoxide and acetate precursors on TiO2/Pt/TiO2/SiO2/Si substrates. Relaxor behavior as evidenced by frequency dispersion of the permittivity as a function of temperature was observed, as well as a thickness dependence of the dielectric constant. The highest values of dielectric constant were observed for the thicker 650 nm samples displaying a room temperature dielectric constant near 2000, with a loss tangent of 0.3% at 1 kHz. The

Piezoelectric coatings of PbZrxTi1-xO3 (PZT) were deposited on standard telecommunication fibers. The PZT coatings were produced by reactive de magnetron sputtering of metal targets in pure oxygen atmosphere. The deposition was carried out at substrate temperatures between 500 and 600 degrees C. Film thicknesses are in the range of 1300 to 1500 nm. The device structure under investigation is of the Ti/Pt/PZT/Au type. X-ray diffraction (XRD) scanning electron microscopy (SEM), and electrical measurements wer

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

This paper addresses the problem of time-dependent dielectric breakdown of Pb(Zr,Ti)O-3 (PZT) thin films. It is shown by using constant-current breakdown measurements, that for PZT film capacitors with Pt and SrRuO3 (SRO) electrodes the breakdown onset is controlled by charge to breakdown (Q(BR)) rather than the voltage applied to the capacitor. The QBR value for the asymmetrical Pt/SrRuO3/PZT/Pt capacitors is found to be much higher that for the Pt/PZT/Pt system. Polarization fatigue caused by bipolar volt

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

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

Self-polarization effect in Pb(Zr,Ti)O-3 thin films

Gas spectrometry based on a pyroelectric thin film array

Adsorbate-localized states at water-covered (100) SrTiO[sub 3] surfaces

Non-Kolmogorov-Avrami switching kinetics in ferroelectric thin films

Quantum well ZnCdTe/CdTe structures with integrated ferroelectric gates

Microscopic aspects of the region-by-region polarization reversal kinetics of polycrystalline ferroelectric Pb(Zr,Ti)O-3 films

Mechanisms of Pb(Zr0.53Ti0.47)O-3 thin film etching with ECR/RF reactor

Kinetics of polarization reversal in ferroelectric films: role of domain nucleation and domain wall motion

Polarization Reversal in BiFeO3 Capacitors: Complex Behavior Revealed by PFM

Transient photocurrents in lead zirconate titanate thin films

Ferroelectric Gate on AlGaN/GaN Heterostructures

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

Engineering of piezoelectric properties in ferroelectric ceramics and thin films

Dielectric response and structural features of Pb(Sc1/2Ta1/2)O-3 (PST) sol-gel derived thin films

PZT coated optical fibers for acousto-optical modulation

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

Constant-current study of dielectric breakdown of Pb(Zr,Ti)O-3 ferroelectric film capacitors