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Xi Yao - One of the best experts on this subject based on the ideXlab platform.

  • dielectric and magnetic properties of Lead Zirconate Titanate ni ferrite composites
    Materials Research Innovations, 2011
    Co-Authors: J. L. Chen, Zuopeng Xu, B K Wang, Xi Yao
    Abstract:

    Ni0·93Co0·02Cu0·05Fe2O4 and Lead Zirconate Titanate composites with ferroelectric–ferromagnetic characteristics were prepared using the conventional solid state reaction method. The presence of constituent phases in composites was confirmed by X-ray diffraction. The microstructural features of the composites were studied by scanning electron microscopy. The results indicate that the ferrite and piezoelectric phases can coexist in the composites. The variation in dielectric constant with frequency in the range from 40 Hz to 1 MHz and also with temperature (frequency of 1 kHz) has been studied. Typical magnetic hysteresis loops of composites have been observed at room temperature. The permeability of composites decreases with the increasing content of non-ferromagnetic phase, and the composites preserve their basic properties. Hence, these composites, Lead Zirconate Titanate–Ni0·93Co0·02Cu0·05Fe2O4, are a good candidate as magnetoelectric material.

  • Dielectric and magnetic properties of Lead Zirconate Titanate/Ni ferrite composites
    Materials Research Innovations, 2011
    Co-Authors: J. L. Chen, Zuopeng Xu, B K Wang, Xi Yao
    Abstract:

    Ni0·93Co0·02Cu0·05Fe2O4 and Lead Zirconate Titanate composites with ferroelectric–ferromagnetic characteristics were prepared using the conventional solid state reaction method. The presence of constituent phases in composites was confirmed by X-ray diffraction. The microstructural features of the composites were studied by scanning electron microscopy. The results indicate that the ferrite and piezoelectric phases can coexist in the composites. The variation in dielectric constant with frequency in the range from 40 Hz to 1 MHz and also with temperature (frequency of 1 kHz) has been studied. Typical magnetic hysteresis loops of composites have been observed at room temperature. The permeability of composites decreases with the increasing content of non-ferromagnetic phase, and the composites preserve their basic properties. Hence, these composites, Lead Zirconate Titanate–Ni0·93Co0·02Cu0·05Fe2O4, are a good candidate as magnetoelectric material.

  • Controlled Crystallization in Lead Zirconate Titanate Glass‐Ceramics Prepared by the Sol‐Gel Process
    Journal of the American Ceramic Society, 2005
    Co-Authors: Kui Yao, Xi Yao, Liangying Zhang, Weiguang Zhu
    Abstract:

    Lead Titanate and Lead Zirconate Titanate grains were grown in situfrom Lead-titanium-boron-silicon and Lead-zirconium-titanium-boron-silicon gels prepared via the sol-gel method. The Lead Zirconate Titanate grains were much smaller and more uniform than Lead Titanate grains grown from gels of similar composition. The crystallization mechanisms of the two systems were studied via scanning electron microscopy, X-ray diffractometry, Raman spectroscopy, and differential thermal analysis. Crystallization had a tendency to begin near the surface or at defects in the Lead Titanate system, whereas it was controlled by the original precipitated nuclei of tetragonal zirconia particles in the Lead Zirconate Titanate system. Controlled bulk crystallization may explain the finer structure of the resultant Lead Zirconate Titanate glass-ceramic.

  • Thermal expansion in Lead Zirconate Titanate
    Chinese Science Bulletin, 2002
    Co-Authors: Yujun Feng, Xi Yao
    Abstract:

    The volume anomalies with temperature variations in tin-modified Lead Zirconate Titanate ceramics are investigated. Experimental results show that the volume changes are related to the phase transitions induced with temperature. The magnitude and orientation of crystal volume changes are dependent on the particular phase transition. When antiferroelectrics is transformed to ferroelectrics or paraelectrics the volume expands. Oppositely when ferroelectrics is transformed to antiferroelectrics or paraelectrics the volume contracts. In the transition of antiferroelectric orthorhombic structure to tetragonal structure or ferroelectric low-temperature rhombohedral structure to high-temperature rhombohedral structure, there are also revealed apparent anomalies in the curves of thermal expansion. Among them, the volume strain caused by the transition between antiferroelectrics and ferroelectrics is the biggest in magnitude, and the linear expansion dL/L0 and the expansion coefficient (dL/L 0)/dT can reach 2.8 × 10−3 and 7.5 × 10−4 K−1 respectively.

Diego E. Gallardo - One of the best experts on this subject based on the ideXlab platform.

  • Photochemical growth of silver nanoparticles on c(-) and c(+) domains on Lead Zirconate Titanate thin films.
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

  • photochemical growth of silver nanoparticles on c and c domains on Lead Zirconate Titanate thin films
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

Steve Dunn - One of the best experts on this subject based on the ideXlab platform.

  • photochemical growth of silver nanoparticles on c and c domains on Lead Zirconate Titanate thin films
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

  • Photochemical growth of silver nanoparticles on c(-) and c(+) domains on Lead Zirconate Titanate thin films.
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

  • Photo-reduction of silver salts on highly heterogeneous Lead Zirconate Titanate
    Nanotechnology, 2007
    Co-Authors: Paul M. Jones, Steve Dunn
    Abstract:

    This paper presents the work undertaken to determine the influences on the photo-induced growth of silver nanoclusters on the surfaces of Lead Zirconate Titanate thin films. The Lead Zirconate Titanate films were grown on indium tin oxide coated glass. They exhibited a highly textured surface and can be treated as wide bandgap semiconductors that exhibit ferroelectric behaviour. We show that there is a preferential deposition of silver metal on the ferroelectric films that is related not only to the polarization state of the ferroelectric domains but also to the surface defects such as grain boundaries and defects within the film. The greatest deposition rates are found to occur at grain boundaries where there is an approximately 40:1 ratio of silver clusters when compared to the native positive domains exhibited by the Lead Zirconate Titanate. We propose that the mechanism for cluster growth depends on the availability, and diffusion rate, of electrons into the growing cluster and that the clusters grow from a discrete nucleation point. We also show that the growth of a monolayer of silver is sufficient to prevent the formation of electron–hole pairs by blocking the UV irradiation and that the silver nanoparticles are readily removed from the surface using an ultrasonic bath Leading to a possible new method of manufacturing metal nanoparticles.

Paul M. Jones - One of the best experts on this subject based on the ideXlab platform.

  • photochemical growth of silver nanoparticles on c and c domains on Lead Zirconate Titanate thin films
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

  • Photochemical growth of silver nanoparticles on c(-) and c(+) domains on Lead Zirconate Titanate thin films.
    Journal of the American Chemical Society, 2007
    Co-Authors: Steve Dunn, Paul M. Jones, Diego E. Gallardo
    Abstract:

    The photochemical growth of silver nanoparticles on the negative domains of Lead Zirconate Titanate thin films is reported. A sample of highly [100] orientated Lead Zirconate Titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the Lead Zirconate Titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination Leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.

  • Photo-reduction of silver salts on highly heterogeneous Lead Zirconate Titanate
    Nanotechnology, 2007
    Co-Authors: Paul M. Jones, Steve Dunn
    Abstract:

    This paper presents the work undertaken to determine the influences on the photo-induced growth of silver nanoclusters on the surfaces of Lead Zirconate Titanate thin films. The Lead Zirconate Titanate films were grown on indium tin oxide coated glass. They exhibited a highly textured surface and can be treated as wide bandgap semiconductors that exhibit ferroelectric behaviour. We show that there is a preferential deposition of silver metal on the ferroelectric films that is related not only to the polarization state of the ferroelectric domains but also to the surface defects such as grain boundaries and defects within the film. The greatest deposition rates are found to occur at grain boundaries where there is an approximately 40:1 ratio of silver clusters when compared to the native positive domains exhibited by the Lead Zirconate Titanate. We propose that the mechanism for cluster growth depends on the availability, and diffusion rate, of electrons into the growing cluster and that the clusters grow from a discrete nucleation point. We also show that the growth of a monolayer of silver is sufficient to prevent the formation of electron–hole pairs by blocking the UV irradiation and that the silver nanoparticles are readily removed from the surface using an ultrasonic bath Leading to a possible new method of manufacturing metal nanoparticles.

Gang Wang - One of the best experts on this subject based on the ideXlab platform.

  • modeling and analysis of lamb wave propagation in a beam under Lead Zirconate Titanate actuation and sensing
    Journal of Intelligent Material Systems and Structures, 2015
    Co-Authors: Vishnu Prasad Venugopal, Gang Wang
    Abstract:

    Lead Zirconate Titanate actuators and sensors have been the widely used in Lamb wave–based damage detection applications. The excitation frequency, waveform, and wave propagation characteristics should be comprehensively considered to effectively conduct diagnosis of incipient forms of damage. In this article, we investigate Lamb wave propagation in a beam under Lead Zirconate Titanate actuation/sensing, in which the Lead Zirconate Titanate effects are included. First, mathematical models are developed to account for both unimorph (i.e. sensor mode) and bimorph (i.e. actuator mode) configurations. The Timoshenko beam theory is adopted for both base beam and Lead Zirconate Titanate layers to accommodate high-frequency responses. Second, the fully coupled electromechanical governing equations are determined and solved in an analytical form to formulate the spectral finite element model. Finally, parametric studies are carried out to determine the optimal actuation frequency, sensor size, actuator, and senso...

  • Lead Zirconate Titanate behaviors in an LDMOS
    Chinese Physics B, 2013
    Co-Authors: Yahong Zhai, Weirong Huo, Xue Fan, Gang Wang
    Abstract:

    The behaviors of Lead Zirconate Titanate (PZT) deposited as the dielectric for high-voltage devices are investigated experimentally and theoretically. The devices demonstrate not only high breakdown voltages above 350 V, but also excellent memory behaviors. A drain current?gate voltage (ID?VG) memory window of about 2.2 V is obtained at the sweep voltages of ?10 V for the 350-V laterally diffused metal oxide semiconductor (LDMOS). The retention time of about 270 s is recorded for the LDMOS through a controlled ID?VG measurement. The LDMOS with memory behaviors has potential to be applied in future power conversion circuits to boost the performance of the energy conversion system.