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L. Eric Cross - One of the best experts on this subject based on the ideXlab platform.

  • Identification of the Morphotropic Phase Boundary in the lead scandium tantalate-lead titanate solid solution system
    Journal of Materials Science, 1997
    Co-Authors: J. R Giniewicz, Amar S. Bhalla, L. Eric Cross
    Abstract:

    A Morphotropic Phase Boundary between rhombohedral and tetragonal Phase regions has been identified to lie in the composition range x=0.4–0.45 by means of X-ray diffraction, and dielectric, pyroelectric, and piezoelectric measurements. Some curvature to this Boundary at high temperatures is indicated in the temperature dependences of the dielectric constants and pyroelectric coefficients of poled specimens.

  • Identification of the Morphotropic Phase Boundary in the lead scandium tantalate–lead titanate solid solution system
    Journal of Materials Science, 1997
    Co-Authors: J. R Giniewicz, Amar S. Bhalla, L. Eric Cross
    Abstract:

    A Morphotropic Phase Boundary between rhombohedral and tetragonal Phase regions has been identified to lie in the composition range x=0.4–0.45 by means of X-ray diffraction, and dielectric, pyroelectric, and piezoelectric measurements. Some curvature to this Boundary at high temperatures is indicated in the temperature dependences of the dielectric constants and pyroelectric coefficients of poled specimens.

  • theoretical model for the Morphotropic Phase Boundary in lead zirconate lead titanate solid solution
    Physical Review B, 1993
    Co-Authors: L. Eric Cross
    Abstract:

    A statistical model is proposed to address the problem of two-Phase coexistence near the Morphotropic Phase Boundary (MPB) in Pb(Zr 1-x Ti x )O 3 solid-solution series. Functional forms for the molar fractions of tetragonal and rhombohedral Phases inside the coexistence region are obtained, which may be used to replace the lever rule to describe the Phase mixing in a complete binary solid-solution series without solubility gap. The model predicts that the width of this coexistence region is inversely proportional to the volume of each element in the statistical ensemble

  • Polarization mechanisms of Morphotropic Phase Boundary lead barium niobate (PBN) compositions
    Journal of Applied Physics, 1990
    Co-Authors: Amar S. Bhalla, Z. P. Chang, Clive A Randall, L. Eric Cross
    Abstract:

    Investigations of the polarization mechanisms in tungsten bronze relaxor ferroelectrics, Pb1–xBaxNb2O6 (PBN[(1−x) %]), in particular, of the Morphotropic Phase Boundary compositions have been carried out for both ceramics and bulk crystals by means of electrical, thermal, optical, and electron‐microscopic methods. Relations of Phase‐transition behavior with compositional and polarizational fluctuations have been carefully studied. Instead of a sharp Boundary composition, it is found that a rather wide composition range, 1−x≊0.63±0.03 in Pb1−xBaxNb2O6, corresponds to the orthorhombic and tetragonal Morphotropic Phase Boundary. It is demonstrated with the help of optical conoscopic interference figures that for the near‐Morphotropic Phase Boundary single crystal PBN of tetragonal symmetry, the polarization vector can be switched orthogonally to an orthorhombic Phase simply by the application of an electric field, which authenticates optically the 90° polarization rotation. A transmission electron microscope...

Amar S. Bhalla - One of the best experts on this subject based on the ideXlab platform.

  • Dielectric, pyroelectric properties, and Morphotropic Phase Boundary in La-doped (1 − x)Pb(Mg1/3Ta2/3)−xPbTiO3 solid solution ceramics
    Ferroelectrics, 2011
    Co-Authors: Y. J. Kim, Seong Won Choi, Amar S. Bhalla
    Abstract:

    Abstract Dielectric and pyroelectric properties of relaxor ferroelectric in the (1 - x)(Pbl-3y/2Lay)(Mg1/3Ta2/3)-xPbTiO3 (PMT-PT) solid solution series have been investigated. The dielectric constant and loss of ceramic samples were determined. The pyroelectric coefficient and spontaneous polarization were measured by the static Byer-Roundy method as a function of temperature for various compositions in the La-doped PMT-PT system. The position of the Morphotropic Phase Boundary in PMT-PT appeared not to be affected by La2O3 addition. Lanthanum-doping resulted in a reduction of grain size and shifting of the Tc by about 25°C/mole% downward in the PMT-PT system. Dielectric constants and pyroelectric coefficients for La-doped PMT-PT are much larger compared to the undoped PMT-PT system. Further additions of La2O3 could be used to shift the Tc downward without significantly changing the dielectric behavior. In the present study no clear Morphotropic Phase Boundary (MPB) has been identified. A two-Phase region...

  • Some comments on the Morphotropic Phase Boundary and property diagrams in ferroelectric relaxor systems
    Materials Letters, 2002
    Co-Authors: Amar S. Bhalla, Edward F Alberta
    Abstract:

    Abstract Morphotropic Phase Boundary compositions are very attractive for designing various electronic sensors, capacitors and piezoelectric transducers. Therefore, highly reliable and accurate structure–property diagrams in relaxor ferroelectric systems are desirable. This paper comments on, and draws attention to, certain important points which researchers should take into consideration while drawing structure–property diagrams.

  • Identification of the Morphotropic Phase Boundary in the lead scandium tantalate–lead titanate solid solution system
    Journal of Materials Science, 1997
    Co-Authors: J. R Giniewicz, Amar S. Bhalla, L. Eric Cross
    Abstract:

    A Morphotropic Phase Boundary between rhombohedral and tetragonal Phase regions has been identified to lie in the composition range x=0.4–0.45 by means of X-ray diffraction, and dielectric, pyroelectric, and piezoelectric measurements. Some curvature to this Boundary at high temperatures is indicated in the temperature dependences of the dielectric constants and pyroelectric coefficients of poled specimens.

  • Identification of the Morphotropic Phase Boundary in the lead scandium tantalate-lead titanate solid solution system
    Journal of Materials Science, 1997
    Co-Authors: J. R Giniewicz, Amar S. Bhalla, L. Eric Cross
    Abstract:

    A Morphotropic Phase Boundary between rhombohedral and tetragonal Phase regions has been identified to lie in the composition range x=0.4–0.45 by means of X-ray diffraction, and dielectric, pyroelectric, and piezoelectric measurements. Some curvature to this Boundary at high temperatures is indicated in the temperature dependences of the dielectric constants and pyroelectric coefficients of poled specimens.

  • Morphotropic Phase Boundary in relaxor ferroelectric pb(mg1/3nb2/3)o3 ceramics
    Ferroelectrics, 1996
    Co-Authors: Seong Won Choi, Jong Man Jung, Amar S. Bhalla
    Abstract:

    Abstract The stability of the perovskite Phase was studied as a function of sintering temperature. Dielectric, piezoelectric and pyroelectric properties of relaxor ferroelectric in the (1 – x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 solid solution series have been investigated. An important contribution to the dielectric, pyroelectric and piezoelectric behaviors for the solid solution compositions close to the Morphotropic Phase Boundary between rhombohedral and tetragonal regions existing in the grains of the ceramic were observed. The anomalous dielectric and pyroelectric behaviors are observed at the composition x = 0.275-0.325 mole% PT content in the vicinity of the Morphotropic Phase Boundary.

Dhananjai Pandey - One of the best experts on this subject based on the ideXlab platform.

Robert S. Feigelson - One of the best experts on this subject based on the ideXlab platform.

  • Ferroelectric properties of tetragonal lead barium niobate (Pb 1− x Ba x Nb 2 O 6 ) crystals near the Morphotropic Phase Boundary
    Journal of Materials Research, 1998
    Co-Authors: Robert S. Feigelson
    Abstract:

    Tungsten bronze ferroelectrics with a Morphotropic Phase Boundary (MPB) have become increasingly important for a variety of applications because of their enhanced and unique properties near the MPB. Lead barium niobate (Pb 1− x Ba x Nb 2 O 6 ) crystals, which have a Morphotropic Phase Boundary between the orthorhombic (1 − x > ∼0.63) and tetragonal (1 − x , μ m. Crystals could be poled by slowly cooling from above the Curie temperatures (300–400 °C) under a dc field of 5 V/mm. The spontaneous polarization P s of tetragonal Pb 1− x Ba x Nb 2 O 6 was found to be in the range of 0.40–0.70 μ C/mm 2 at room temperature depending on composition and increased as the composition approached Morphotropic Phase Boundary (1 − x = ∼0.63), as expected.

  • FERROELECTRIC PROPERTIES OF TETRAGONAL LEAD BARIUM NIOBATE (PB1-XBAXNB2O6)CRYSTALS NEAR THE Morphotropic Phase Boundary
    Journal of Materials Research, 1998
    Co-Authors: Myeongkyu Lee, Robert S. Feigelson
    Abstract:

    Tungsten bronze ferroelectrics with a Morphotropic Phase Boundary (MPB) have become increasingly important for a variety of applications because of their enhanced and unique properties near the MPB. Lead barium niobate (Pb 1− x Ba x Nb 2 O 6 ) crystals, which have a Morphotropic Phase Boundary between the orthorhombic (1 − x > ∼0.63) and tetragonal (1 − x , μ m. Crystals could be poled by slowly cooling from above the Curie temperatures (300–400 °C) under a dc field of 5 V/mm. The spontaneous polarization P s of tetragonal Pb 1− x Ba x Nb 2 O 6 was found to be in the range of 0.40–0.70 μ C/mm 2 at room temperature depending on composition and increased as the composition approached Morphotropic Phase Boundary (1 − x = ∼0.63), as expected.

Xiaowen Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Effects of hydrostatic pressure on Pb(Zr1−xTix)O3 near the Morphotropic Phase Boundary
    Journal of Applied Physics, 2010
    Co-Authors: Chaoye Wu, Wenhui Duan, Xiaowen Zhang
    Abstract:

    A first-principles-derived effective Hamiltonian is adopted to simulate the effects of high-pressure on Pb(Zr1−xTix)O3 near the Morphotropic Phase Boundary. With increasing pressure, the induced tetragonal-to-monoclinic and monoclinic-to-rhombohedral Phase transitions are observed at low temperatures, which are accompanied by significantly enhanced piezoelectric responses. By determining the pressure-temperature Phase diagram, it was revealed that the M Phase resides in a narrow region between the T and R Phases with inclining boundaries.

  • Morphotropic Phase Boundary and electrical properties of k1 xnaxnbo3 lead free ceramics
    Applied Physics Letters, 2009
    Co-Authors: Xiaowen Zhang, Kepi Chen
    Abstract:

    Lead-free K1−xNaxNbO3 ceramics with x=0.48–0.54 were prepared by a conventional solid-state reaction method to investigate the influence of the K/Na ratio on Phase structures and electrical properties. The results suggest that a typical Morphotropic Phase Boundary exists at x=0.52–0.525, separating the monoclinic and orthorhombic Phases. The sample with the composition near x=0.52 shows the maximum values of the piezoelectric constant (d33=160 pC/N) and the electromechanical coupling coefficient (kt=47%). The results provide a helpful guidance to consider the optimal ratio of K to Na for designing and developing new (K,Na)NbO3-based ceramics.

  • Morphotropic Phase Boundary in Pb(Ni1/3Nb2/3)O3–PbTiO3 solid solution system
    Materials Science and Engineering B-advanced Functional Solid-state Materials, 2003
    Co-Authors: Kepi Chen, Xiaowen Zhang, Jun Wang
    Abstract:

    Abstract (1− x )Pb(Ni 1/3 Nb 2/3 )O 3 – x PbTiO 3 ( x =0.28–0.42) solid solution was synthesized by a B-site precursor method and characterized by high-resolution synchrotron radiation X-rays diffraction and dielectric measurement. The results indicated that composition induced Phase transition is not continuous, and the intermediate monoclinic Phase may exist in Morphotropic Phase Boundary between rhombohedral and tetragonal Phases in this solid solution system.