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Shashank Priya - One of the best experts on this subject based on the ideXlab platform.

  • high energy density Ceramic Composition in the system pb zr ti o3 pb zn ni 1 3nb2 3 o3
    Journal of the American Ceramic Society, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This study reports a high-energy density piezoelectric polycrystalline Ceramic Composition in the system Pb(Zr 1-x Ti x ) 03-Pb[(Zn 1-y Ni y ) 1/3 Nb 2/3 ]O 3 (PZT-PZNN). Two different Zr/Ti ratios in the PZT system were investigated: 52/48 corresponding to morphotropic phase boundary (MPB) and 56/44 corresponding to the tetragonal phase. The Compositions investigated in this study are represented as: 0.9Pb(Zr 0.52 Ti 0.48 ) O 3 -0.1Pb(Zn 1/3 Nb 2/3 )O 3 [0.9PZT (52:48)-0.1PZN]+y wt% MnCO 3 , where y varies from 0 to 0.9 wt% and 0.9Pb (Zr 0.56 Ti 0.44 )O 3 -0.1Pb[(Zn 0.8 Ni 0.2 ) 1/3 Nb 2/3 ]O 3 [0.9PZT (56:44)-0.1PZNN] +y mol% MnO 2 , where y varies from 1 to 3 mol%. A high-energy density material is characterized by the large magnitude of the product of the piezoelectric voltage constant (g) and the piezoelectric strain constant (d) given as (dg). The condition for obtaining large magnitude of dg was derived to be as |d| = e n , where e is the permittivity of the material and n is a material constant having a lower limit of 0.5. The d 33 .g 33 value of the samples having Composition 0.9 PZT (56:44)-0.1 PZNN+2 mol% MnO 2 (sintered in two steps at 1100°-1000°C) was found to be 18456.2×10 -15 m 2 /N, which, to the knowledge of the authors, is the highest value reported for polycrystalline Ceramics. This Composition was also found to exhibit a high magnitude of g 33 as 83.1 V·(m·N) -1 , corresponding to the magnitude of n as 1.126.

  • realization of high energy density polycrystalline piezoelectric Ceramics
    Applied Physics Letters, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This letter reports a high energy density piezoelectric material in the system given as: Pb[(Zr0.52Ti0.48)O3]1−x[(Zn1∕3Nb2∕3)O3]x+yMnCO3, where x=0.1 and y varies from 0.5to0.9wt%. A piezoelectric material with high energy density is characterized by a high product of piezoelectric voltage constant (g) and piezoelectric strain constant (d). The condition for obtaining large magnitude of g constant was derived to be as ∣d∣=en, where e is the permittivity of the material and n is constant having lower bound of 0.5. It was found that for all practical polycrystalline piezoelectric Ceramic materials the magnitude of n lies in the range of 1.1–1.30 and as the magnitude of n decreases towards unity a giant enhancement in the magnitude of g was obtained. A two step sintering process was developed to optimize a polycrystalline Ceramic Composition with low magnitude of n. For the optimized Composition the value of g33 and d33 was found to be 55.56×10−3m2∕C and 291×10−12C∕N, respectively, yielding the magnitude pro...

  • High‐Energy Density Ceramic Composition in the System Pb(Zr,Ti)O3–Pb[(Zn,Ni)1/3Nb2/3]O3
    Journal of the American Ceramic Society, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This study reports a high-energy density piezoelectric polycrystalline Ceramic Composition in the system Pb(Zr 1-x Ti x ) 03-Pb[(Zn 1-y Ni y ) 1/3 Nb 2/3 ]O 3 (PZT-PZNN). Two different Zr/Ti ratios in the PZT system were investigated: 52/48 corresponding to morphotropic phase boundary (MPB) and 56/44 corresponding to the tetragonal phase. The Compositions investigated in this study are represented as: 0.9Pb(Zr 0.52 Ti 0.48 ) O 3 -0.1Pb(Zn 1/3 Nb 2/3 )O 3 [0.9PZT (52:48)-0.1PZN]+y wt% MnCO 3 , where y varies from 0 to 0.9 wt% and 0.9Pb (Zr 0.56 Ti 0.44 )O 3 -0.1Pb[(Zn 0.8 Ni 0.2 ) 1/3 Nb 2/3 ]O 3 [0.9PZT (56:44)-0.1PZNN] +y mol% MnO 2 , where y varies from 1 to 3 mol%. A high-energy density material is characterized by the large magnitude of the product of the piezoelectric voltage constant (g) and the piezoelectric strain constant (d) given as (dg). The condition for obtaining large magnitude of dg was derived to be as |d| = e n , where e is the permittivity of the material and n is a material constant having a lower limit of 0.5. The d 33 .g 33 value of the samples having Composition 0.9 PZT (56:44)-0.1 PZNN+2 mol% MnO 2 (sintered in two steps at 1100°-1000°C) was found to be 18456.2×10 -15 m 2 /N, which, to the knowledge of the authors, is the highest value reported for polycrystalline Ceramics. This Composition was also found to exhibit a high magnitude of g 33 as 83.1 V·(m·N) -1 , corresponding to the magnitude of n as 1.126.

Rashed Adnan Islam - One of the best experts on this subject based on the ideXlab platform.

  • high energy density Ceramic Composition in the system pb zr ti o3 pb zn ni 1 3nb2 3 o3
    Journal of the American Ceramic Society, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This study reports a high-energy density piezoelectric polycrystalline Ceramic Composition in the system Pb(Zr 1-x Ti x ) 03-Pb[(Zn 1-y Ni y ) 1/3 Nb 2/3 ]O 3 (PZT-PZNN). Two different Zr/Ti ratios in the PZT system were investigated: 52/48 corresponding to morphotropic phase boundary (MPB) and 56/44 corresponding to the tetragonal phase. The Compositions investigated in this study are represented as: 0.9Pb(Zr 0.52 Ti 0.48 ) O 3 -0.1Pb(Zn 1/3 Nb 2/3 )O 3 [0.9PZT (52:48)-0.1PZN]+y wt% MnCO 3 , where y varies from 0 to 0.9 wt% and 0.9Pb (Zr 0.56 Ti 0.44 )O 3 -0.1Pb[(Zn 0.8 Ni 0.2 ) 1/3 Nb 2/3 ]O 3 [0.9PZT (56:44)-0.1PZNN] +y mol% MnO 2 , where y varies from 1 to 3 mol%. A high-energy density material is characterized by the large magnitude of the product of the piezoelectric voltage constant (g) and the piezoelectric strain constant (d) given as (dg). The condition for obtaining large magnitude of dg was derived to be as |d| = e n , where e is the permittivity of the material and n is a material constant having a lower limit of 0.5. The d 33 .g 33 value of the samples having Composition 0.9 PZT (56:44)-0.1 PZNN+2 mol% MnO 2 (sintered in two steps at 1100°-1000°C) was found to be 18456.2×10 -15 m 2 /N, which, to the knowledge of the authors, is the highest value reported for polycrystalline Ceramics. This Composition was also found to exhibit a high magnitude of g 33 as 83.1 V·(m·N) -1 , corresponding to the magnitude of n as 1.126.

  • realization of high energy density polycrystalline piezoelectric Ceramics
    Applied Physics Letters, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This letter reports a high energy density piezoelectric material in the system given as: Pb[(Zr0.52Ti0.48)O3]1−x[(Zn1∕3Nb2∕3)O3]x+yMnCO3, where x=0.1 and y varies from 0.5to0.9wt%. A piezoelectric material with high energy density is characterized by a high product of piezoelectric voltage constant (g) and piezoelectric strain constant (d). The condition for obtaining large magnitude of g constant was derived to be as ∣d∣=en, where e is the permittivity of the material and n is constant having lower bound of 0.5. It was found that for all practical polycrystalline piezoelectric Ceramic materials the magnitude of n lies in the range of 1.1–1.30 and as the magnitude of n decreases towards unity a giant enhancement in the magnitude of g was obtained. A two step sintering process was developed to optimize a polycrystalline Ceramic Composition with low magnitude of n. For the optimized Composition the value of g33 and d33 was found to be 55.56×10−3m2∕C and 291×10−12C∕N, respectively, yielding the magnitude pro...

  • High‐Energy Density Ceramic Composition in the System Pb(Zr,Ti)O3–Pb[(Zn,Ni)1/3Nb2/3]O3
    Journal of the American Ceramic Society, 2006
    Co-Authors: Rashed Adnan Islam, Shashank Priya
    Abstract:

    This study reports a high-energy density piezoelectric polycrystalline Ceramic Composition in the system Pb(Zr 1-x Ti x ) 03-Pb[(Zn 1-y Ni y ) 1/3 Nb 2/3 ]O 3 (PZT-PZNN). Two different Zr/Ti ratios in the PZT system were investigated: 52/48 corresponding to morphotropic phase boundary (MPB) and 56/44 corresponding to the tetragonal phase. The Compositions investigated in this study are represented as: 0.9Pb(Zr 0.52 Ti 0.48 ) O 3 -0.1Pb(Zn 1/3 Nb 2/3 )O 3 [0.9PZT (52:48)-0.1PZN]+y wt% MnCO 3 , where y varies from 0 to 0.9 wt% and 0.9Pb (Zr 0.56 Ti 0.44 )O 3 -0.1Pb[(Zn 0.8 Ni 0.2 ) 1/3 Nb 2/3 ]O 3 [0.9PZT (56:44)-0.1PZNN] +y mol% MnO 2 , where y varies from 1 to 3 mol%. A high-energy density material is characterized by the large magnitude of the product of the piezoelectric voltage constant (g) and the piezoelectric strain constant (d) given as (dg). The condition for obtaining large magnitude of dg was derived to be as |d| = e n , where e is the permittivity of the material and n is a material constant having a lower limit of 0.5. The d 33 .g 33 value of the samples having Composition 0.9 PZT (56:44)-0.1 PZNN+2 mol% MnO 2 (sintered in two steps at 1100°-1000°C) was found to be 18456.2×10 -15 m 2 /N, which, to the knowledge of the authors, is the highest value reported for polycrystalline Ceramics. This Composition was also found to exhibit a high magnitude of g 33 as 83.1 V·(m·N) -1 , corresponding to the magnitude of n as 1.126.

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

  • effect of bioactive Ceramic Composition and structure on in vitro behavior iii porous versus dense Ceramics
    Journal of Biomedical Materials Research, 1994
    Co-Authors: S Radin, Paul Ducheyne
    Abstract:

    In vitro reaction kinetics of surface transformations of porous and dense bioactive Ceramics were studied after immersion in simulated physiologic solution (SPS). Porous Ceramics with identical macroporosity were commercially obtained: calcium carbonate marine coral (I-CC), coralline HA (I-HA), and a product, labeled as beta-tricalcium phosphate, which was partially transformed into beta-calcium pyrophosphate (I-beta-CP). Previously studied dense Ceramics were used for comparison: Ca-deficient HA (CDHA), stoichiometric HA, both well and not well crystallized (wc and nwc s-HA), beta- and alpha-tricalcium phosphate (beta- and alpha-TCP). The induction time to precipitation increased as follows: CDHA, nwc HA < wc HA, I-HA < beta-TCP, I-CC << I-beta-CP. The reaction kinetics of Ceramics with identical macroporosity varied substantially depending on Composition, crystal structure, and ultrastructure. One of the porous Ceramics, I-beta-CP, showed an inhibiting effect on precipitation reactions.

  • the effect of calcium phosphate Ceramic Composition and structure on in vitro behavior i dissolution
    Journal of Biomedical Materials Research, 1993
    Co-Authors: Paul Ducheyne, S Radin, Linda King
    Abstract:

    Synthetic calcium phosphate Ceramic (CPC) surfaces can be transformed to a biological apatite through a sequence of reactions which include dissolution, precipitation, and ion exchange. By virtue of the reactions being material-dependent, it is important to determine parametric rate effects. In this study we focused on the effect of stoichiometry and crystal structure of CPCs on the dissolution kinetics. Monophase, biphase, and multiphase CPCs with a Ca/P ratio equal to or greater than 1.5 were studied. The experiments were performed in a calcium- and phosphate-free Tris buffer solution at pH 7.3. The dissolution behavior of the CPCs studied was found to vary over a wide range. The dissolution rate of the monophase CPCs increased in the order of stoichiometric hydroxyapatite, calcium deficient hydroxyapatite, oxyhydroxyapatite, beta-tricalcium phosphate, alpha-tricalcium phosphate, and tetracalcium phosphate. Dissolution of biphase and multiphase CPCs increased prorated the concentration of more soluble component.

  • The effect of calcium phosphate Ceramic Composition and structure on in vitro behavior. II. Precipitation.
    Journal of biomedical materials research, 1993
    Co-Authors: S R Radin, Paul Ducheyne
    Abstract:

    The formation of a biologically equivalent carbonate-containing apatite on the surface of synthetic calcium phosphate Ceramics (CPC) may be an important step leading to bonding with bone. Reactions of several single phases CPCs upon immersion into a simulated physiologic solution (SPS) with an electrolyte Composition of human plasma were determined. The CPCs covered a wide range of solution stabilities from low-soluble hydroxyapatites (HA) to metastable tricalcium phosphates (TCP) and tetracalcium phosphate (TTCP). Changes in chemical Compositions of SPS and infrared spectral features after CPC immersion were analyzed. New phase formation was observed on all the CPCs. However, kinetics, Compositions, and structures of the new phases were significantly different. The studied CPCs can be characterized by the time to new phase formation in vitro; the minimum time for measurable precipitate formation was found to increase in the order: not-well-crystallized HAs < well-crystallized HAs < alpha-TCP, TTCP < beta-TCP. Among the CPCs only not-well-crystallized HAs led to immediate new phase formation. The metastable CPCs, beta-TCP, alpha-TCP, and TTCP required an induction time during which dissolution occurred. beta-TCP showed the longest induction time and the lowest lattice ion uptake rate of all the CPCs tested. Only the not-well-crystallized HAs elicited immediate formation of carbonated HA. The well-crystallized HAs and beta-TCP did not elicit carbonated apatite formation within the time frame of the experiment. Instead, intermediate phases were formed. On alpha-TCP amorphous calcium phosphate (ACP) with a relatively low carbonate content was formed. TTCP was found to transform extensively to poorly crystallized carbonated apatite after 2 days of immersion.

Gary L. Messing - One of the best experts on this subject based on the ideXlab platform.

  • dielectric and piezoelectric properties of 001 fiber textured 0 675pb mg1 3nb2 3 o3 0 325pbtio3 Ceramics
    Journal of Applied Physics, 2003
    Co-Authors: Edward M. Sabolsky, Susan Troliermckinstry, Gary L. Messing
    Abstract:

    The 0.675Pb(Mg1/3Nb2/3)O3–0.325PbTiO3 (PMN–32.5PT) Ceramic Composition (with 1 wt. % excess PbO) was fiber textured in the 〈001〉 direction by the templated grain growth process using 5 vol % oriented {001}-BaTiO3 platelet crystals as the templates. The templated Ceramics annealed at 1150 °C for 5 h attained texture fractions as high as 0.9. The fiber-textured samples showed an increase in the piezoelectric, electromechanical coupling, and compliance coefficients when poled and measured in the 〈001〉-textured direction. The low drive field (<5 kV/cm) d33 coefficients in the 〈001〉, measured directly from unipolar strain-field measurements, were ∼1150 pC/N. This d33 coefficient is 1.2–1.5 times greater than randomly oriented samples. The poled emax and ert for a 0.9-textured PMN–32.5PT Ceramic were 21 500 and 2450, respectively. Factors limiting further property improvements are discussed.

  • Dielectric and piezoelectric properties of 〈001〉 fiber-textured 0.675Pb(Mg1/3Nb2/3)O3–0.325PbTiO3 Ceramics
    Journal of Applied Physics, 2003
    Co-Authors: Edward M. Sabolsky, Susan Trolier-mckinstry, Gary L. Messing
    Abstract:

    The 0.675Pb(Mg1/3Nb2/3)O3–0.325PbTiO3 (PMN–32.5PT) Ceramic Composition (with 1 wt. % excess PbO) was fiber textured in the 〈001〉 direction by the templated grain growth process using 5 vol % oriented {001}-BaTiO3 platelet crystals as the templates. The templated Ceramics annealed at 1150 °C for 5 h attained texture fractions as high as 0.9. The fiber-textured samples showed an increase in the piezoelectric, electromechanical coupling, and compliance coefficients when poled and measured in the 〈001〉-textured direction. The low drive field (

Vijaya Puri - One of the best experts on this subject based on the ideXlab platform.

  • Composition dependent resistivity of thick film ni 1 x coxmn2o4 0 x 1 ntc thermistors
    Materials Letters, 2006
    Co-Authors: S A Kanade, Vijaya Puri
    Abstract:

    Abstract The fritless thick film NTC thermistor of Composition Ni (1− x ) Co x Mn 2 O 4 : (0 ≤  x  ≤ 1), synthesized by oxalate co-precipitation, were prepared by screen-printing on alumina substrate. The Composition dependent room temperature resistivities, thermistor constant are investigated. The relation between logarithm of resistivity ( ρ ) and reciprocal of absolute temperature for the prepared thick film thermistor was almost linear for all the Compositions studied. The thick film thermistor with Ceramic Composition Ni 0.6 Co 0.4 Mn 2 O 4 was the best with high sensitivity and lowest room temperature resistivity. Highly temperature dependent effects are also observed for temperature below 340 K.