摘要:

Highly oriented PZT, PLZT and PMN thin films were fabricated on various substrates using sol-gel method. The thin films having different orientation were fabricated by different drying conditions for pyrolysis. The preferred orientations of the PZT, PLZT and PMN thin films were observed using XRD(X-ray diffraction). The hysteresis loops, capacitance-voltage, and fatigue characteristics of the films were investigated using an RT66A standardized ferroelectric test system. The dielectric constant and current-voltage characteristics of the films were investigated using impedance analyzer and pA meter, respectively. The films oriented in particular direction showed better electrical characteristics to the randomly oriented films.

ISSN:1058-4587    

DOI:10.1080/10584589508012920

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The application of PVDF (Polyvinylidene fluoride) film in the active control of waterborne noise is under investigation at the Aeronautical and Maritime Research Laboratory (AMRL), Melbourne, Australia. The film is used in both sensor and actuator designs. The compliant nature of the film provides for ease of application to curved surfaces, however, its performance begins to deteriorate at temperatures above 70°C to 80°C, with a maximum operating temperature of 100°C. This may put a significant constraint on its application, particularly when used as an actuator where deleterious hot spots are easily generated in the area of electrical contacts. In this paper, we mainly present the work on an actuator for the control of noise in water-filled pipes, and briefly discuss a spatial sensor design for the control of hydroacoustic noise radiated from a rib-stiffened panel.

ISSN:1058-4587    

DOI:10.1080/10584589508012921

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We proposed a MFMIS structure having a floating gate as a bottom electrode between a ferroelectric thin film and the gate SiO2. Conventional gate SiO2can be used and ferroelectric thin films can be grown on bottom electrodes which have a good matching with the ferroelectric materials due to adopt the MFMIS structure. Ir and IrO2on poly-Si were used as floating gate. When a IrO2layer was formed between PZT and poly-Si, a high-quality PZT thin film was obtained and the PZT films show no fatigue up to 1012cycles of switching pulses. From the ID-VGcharacteristics measurement for 1·2 μm P-ch MFMIS FET, the shift in Vthor the memory window for a bias sweep of ±15V was about 3·3V. The difference of ID-VDcurves which corresponded to ID-VGcharacteristics were found between before and after a programming pulse was applied.

ISSN:1058-4587    

DOI:10.1080/10584589508012922

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Ionic crystals with large cations based on organic methyl-ammonium structure and large anions based on metal halide groupings show interesting ferroelectric behaviour. This paper investigates the role of H-bonding in such crystals it so far as it influences ferroelectric behaviour.

ISSN:1058-4587    

DOI:10.1080/10584589508012923

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

MIS heterostructures have been fabricated with a 56 nm film of ferroelectric polymer as the insulating layer. High frequency C-V measurements have been made at room temperature, for bias voltages from -5 V to +5 V. A shift of the observed C-V curve from the theoretical curve indicates the presence of fixed positive charges, with density of 0·52 mC m−2, in the polymer layer. Injected and polarisation charges also shift the curves, depending on the direction and sweep rate of the bias voltage. At bias voltages above +1 V dipole movement in the polymer reduces the shielding of inversion layers from depletion region, leading to a widening of the depletion region and a consequent decrease in capacitance.

ISSN:1058-4587    

DOI:10.1080/10584589508012924

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

0–3 composites of lead zirconate titanate (PZT) and P(VDF-TrFE) (piezoelectric copolymer of polyvinylidene fluoride and trifluoroethylene) with different volume fraction of piezoelectric ceramic were fabricated. The composites must be polarized by exposure to a high electric field to elicit piezoelectric response. One of the major consideration for poling a composite is the ratio of the resistivities of constituent phases since it governs the effective poling field across each phase. It is observed that the resistivity of the copolymer shows hysteresis upon heating and cooling, and abrupt changes are found at its Curie transition temperature upon heating (Tc↑) and on cooling (Tc↓). Previous reports stated that PZT/copolymer 0–3 composites of 50 volume percent ceramic do not exhibit piezoelectric response because the piezoelectric constants of the two materials are opposite in sign and cancellation occurs. In the present work, different poling conditions are used to pole the two phases oppositely so that the piezoelectric responses of the two phases reinforce each other. Details of poling and the resulting composite properties are reported.

ISSN:1058-4587    

DOI:10.1080/10584589508012925

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Experimental observation of the static and dynamic response of monocrystalline lead magnesium niobate, Pb(Mg1/3Nb2/3)O3(PMN), at moderate power c. w. laser irradiation shows five distinct regimes depending on the beamwidth and wavefront curvature of the incident Gaussian laser beam. In one of these regimes, the system exhibits multistability and transient aperiodic regenerative oscillations similar to those observed previously in ceramic PMN. In the other four regimes, thermal focussing and/or defocussing combine with nonlinear Fabry-Perot resonances to produce qualitatively different responses. The thermal relaxation time is calculated theoretically as 1 - 500 s, about 103longer than earlier estimates and in agreement with experiment. Damage thresholds are also discussed.

ISSN:1058-4587    

DOI:10.1080/10584589508012926

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Multistability and bistable oscillation in the ferroelectric material PMN was found to be very sensitive to laser power, specimen temperature, ambient pressure and flow rate of air past the specimen (J. F. Scott and T. Chen, Integrated Ferroelectrics, 1, 71(1992)). PMN has the potential to make new photonic sensors due to its figure of merit (better, except for speed, than semiconductor materials such as ZnSe). In this paper, an explanation of experimental results is given. The initial temperature dependence of the time behaviour of the transmitted light intensity and period between the switching events versus switching event number have been obtained and are in qualitatively good agreement with the experimental results.

ISSN:1058-4587    

DOI:10.1080/10584589508012927

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Chemical domain textures of PMN are modelled using next-nearestneighbour Ising (NNNI) models and Monte Carlo methods. These simulations allow us to understand and quantify the local structures of clusters of Nb and Mg atoms and how these interact to form chemical domain walls and other configurations including charged chemical defects.

ISSN:1058-4587    

DOI:10.1080/10584589508012928

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Heavy ion recoil spectrometry employing 77 and 98 MeV127I ions has been used to analyse thin films of barium strontium titanate (BST) at the new heavy ion recoil facility at ANSTO, Lucas Heights. Depth profiles for all major elements and carbon have been obtained. Analysis reveals depletion of oxygen in the BST layer next to the platinum electrode and interdiffusion of strontium and oxygen through the layers.

ISSN:1058-4587    

DOI:10.1080/10584589508012929

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor