DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF (K,Na)NbO3-BASED PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 01 (03) ◽  
pp. 345-349 ◽  
Author(s):  
ERIC A. PATTERSON ◽  
DAVID P. CANN
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Maximum Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dielectric And Piezoelectric Properties

Solid solutions based on Li , Ta and Sb -doped (K0.5Na0.5)NbO3 (KNN) lead-free perovskite systems were created using standard solid-state methods. X-ray diffraction was used to confirm that all compositions were single phase and to verify the phase transition from tetragonal to cubic at TC = 302° C . The three compositions examined, originally developed by Saito and Li , were shown to be strongly ferroelectric with sharp peaks in permittivity present at the Curie temperature. The optimum composition had loss tangent values below 5% up to 100 kHz at room temperature. Bipolar hysteresis measurements showed high values for both maximum polarization (25 and 21 μC/cm2) and remenant polarizations (20 and 16 μC/cm2) for undoped and 0.2 wt% CuO -doped samples. Maximum strain values of greater than 0.23% were observed.

Study of Dielectric and Piezoelectric Properties of (1-x)PZT-xSFN Ceramics Prepared by Conventional Solid State Reaction Method

2020 ◽  
Vol 42 (5) ◽  
pp. 634-634
Author(s):  
Fares Kahoul Fares Kahoul ◽  
Louanes Hamzioui Louanes Hamzioui ◽  
Abderrezak Guemache Abderrezak Guemache ◽  
Michel Aillerie and Ahmed Boutarfaia Michel Aillerie and Ahmed Boutarfaia
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Electrical Parameters ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Dielectric And Piezoelectric Properties

Modified-PZT ceramics with a formula (1-x)Pb(Zr0.53 Ti0.47)O3-xSr(Fe2/3, Nb1/3)O3 (doped with isovalent: Sr2+, acceptor: Fe3+ and Donor: Nb5+ ions) abbreviated as (1-x)PZT-xSFN binary system with varying x (x= 0.02, 0.04, 0.06, 0.08 and 0.10) located near the morphotropic phase boundary (MPB) were prepared by a traditional process in a solid state. All the samples were sintered at a temperature of 1200and#176;C during 2 h. The phase structure, the dielectric and piezoelectric properties of the system were studied. In-phase analysis used X-ray diffraction (XRD) at room temperature indicated that the structure of phase of sintered PZT-SFN ceramics was formed in single-phase with a crystalline structure tetragonal. Raman spectroscopy confirms the presence of this tetragonal phase. The optimum electrical parameters are obtained at 0.94Pb(Zr0.53Ti0.47)O3-0.06Sr(Fe2/3, Nb1/3)O3 system: kp= 66.10 %, d31= 145 pC/N, Qm= 473, tanδ= 1.11 %, and ɛr= 1009.

scholarly journals Structure, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-based lead-free ceramics

RSC Advances ◽  
2018 ◽  
Vol 8 (43) ◽  
pp. 24286-24296 ◽  
Author(s):  
Sushmita Dwivedi ◽  
Tanvi Pareek ◽  
Sunil Kumar
Keyword(s):  
Room Temperature ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
System P ◽  
Lead Free Ceramics ◽  
Diffraction Patterns ◽  
Dielectric And Piezoelectric Properties

Room temperature powder X-ray diffraction patterns of (1 – x)K0.5Na0.5NbO3–xBi(Zn0.5Ti0.5)O3 system.

scholarly journals Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

2016 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lcr Meter ◽  
Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

INFLUENCE OF SAMARIUM SUBSTITUTION ON IMPEDANCE DIELECTRIC AND ELECTROMECHANICAL PROPERTIES OF Pb(1-x)K2xNb2O6

2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Electromechanical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis

Ferroelectric, hysteresis, impedance spectroscopy parameters, AC conductivity, and piezoelectric properties in the ceramics of Pb 0.74 K 0.52 Nb 2 O 6 and Pb 0.74 K 0.13 Sm 0.13 Nb 2 O 6 have been studied. X-ray diffraction study reveals single phase with the orthorhombic structure. The samples were characterized for ferroelectric and impedance spectroscopy properties from room temperature to 600°C. Cole–Cole plots (Z″ versus Z′) are drawn at different temperatures. The results obtained are analyzed to understand the conductivity mechanism in both the samples. The piezoelectric constant d33 has been found to be 96 × 10-12 C/N in PKN.

scholarly journals Thermoelectric properties of LaFeO3 system with doped Ti, Co, Cu

2017 ◽  
Vol 126 (1B) ◽  
pp. 147
Author(s):  
Nguyen Thi Thuy
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Single Phase ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Scanning Electron

<p><strong>Abstract: </strong>LaFeO<sub>3</sub> system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 1250<sup>0</sup>C and 1290<sup>0</sup>C in 10 hours with a heating rate of 3<sup>0</sup>C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe<sup>+3</sup>. The size of particle increase while raising the temperature of sintering. Measuring the resistance which depends on temperature between the room temperature and 1000K, it can be seen that when doping Co, Cu with the nominal component La(Fe<sub>0,2</sub>Co<sub>0,2</sub>Ti<sub>0,6</sub>)O<sub>3</sub> and La(Fe<sub>0,4</sub>Cu<sub>0,1</sub>Ti<sub>0,5</sub>)O<sub>3 </sub>, the conductivity of samples increases respectively. Especially, the conductivity of Cu doped sample is higher than two other samples, and reach the highest conductivity at about 900<sup>0</sup>C, Seebeck coefficient S of La(Fe<sub>0.6</sub>Ti<sub>0.4</sub>)O<sub>3</sub> can be change from positive to negative at the temperature of around 700<sup>0</sup>C.</p>

Phase Formation and Grain Growth of BSCZT Ceramics Prepared by BST-BZT Seed Induced Method

2018 ◽  
Vol 766 ◽  
pp. 175-179
Author(s):  
Jiraporn Dangsak ◽  
Sukum Eitssayeam ◽  
Denis Russell Sweatman ◽  
Uraiwan Intatha
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Phase Formation ◽  
Room Temperature ◽  
Single Phase ◽  
Seed Crystal ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Values

In this work, lead-free Ba0.4Sr0.4Ca0.2Zr0.05Ti0.95O3 ceramics were prepared by the seed induced method using (0.5Ba0.6Sr0.4TiO3–0.5BaZr0.05Ti0.95O3) (BST-BZT) seed. Seed crystals with concentrations of 0, 2.5, 5, 7.5, 10 mol% were mixed with BSCZT powder for 24 h and sintered at 1400 °C for 4 h. The phase formation and microstructure of BSCZT ceramic were characterized by X-ray diffraction technique (XRD) and the scanning electron microscopy (SEM). All samples showed a single phase perovskite structure without impurities and exhibited the existence of the tetragonal phase. The density values of the ceramics decreased from 4.90 to 4.75 g/cm3 with increasing seed crystal concentrations. The grain size of the sample without seed was 3.71 μm, whereas a grain size of 8.99 μm was observed for the sample with 10 mol% seed crystal. The dielectric constant at room temperature at 1 kHz was 1831 for the sample with 10 mol% seed crystal while the dielectric constant of the sample without seed was 1484. From the results in this work, BST-BZT seed can increase grain size and improve the dielectric constant at room temperature.

Effect of Doping Ions on Structure and Electrical Properties of Lead-Free KNN Ceramics

2014 ◽  
Vol 1058 ◽  
pp. 190-195
Author(s):  
Na Yin ◽  
Abolfazl Jalalian ◽  
Zhi Gang Gai ◽  
Lan Ling Zhao ◽  
Xiao Lin Wang
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Boundary Region ◽  
Lead Free ◽  
Vibration Modes ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties

Doping effect on the lattice parameters, vibration modes, dielectric and piezoelectric properties of LiSbO3, LiTaO3 and LiNbO3 substituted lead-free K0.5Na0.5NbO3 (KNN) ceramics are investigated. All compositions are crystallized in morphotropic phase boundary region. Enhanced piezoelectric and electromechanical response d33 ~176–197 pC/N, kp ~45%–48%, and kt~34%–47% obtained in the doped ceramics are due to the presence of the polymorphic phase transition between orthorhombic and tetragonal phase at room temperature.

Effect of La2O3 on the Microstructure and Electrical Properties of 0.82Bi0.5Na0.5TiO3-0.18Bi0.5K0.5TiO3 Ceramics

2011 ◽  
Vol 284-286 ◽  
pp. 1408-1411
Author(s):  
Yan Li ◽  
Yan Jie Zhang ◽  
Rui Qing Chu ◽  
Zhi Jun Xu ◽  
Qian Chen ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Coupling Factor ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Pure Perovskite Structure ◽  
X Ray ◽  
Xrd Patterns ◽  
Dielectric And Piezoelectric Properties

La2O3-doped lead-free 0.82Bi0.5Na0.5TiO3-0.18Bi0.5K0.5TiO3(abbreviated to 0.82BNT-0.18BKT) piezoelectric ceramics were synthesized by the conventional mixed-oxide method, and the effect of La2O3addition on the dielectric and piezoelectric properties was investigated. X-ray diffraction (XRD) patterns show that La2O3diffuses into the lattice of the 0.82BNT-0.18BKT ceramics to form a solid solution with a pure perovskite structure. SEM images indicate that the grain size of the 0.82BNT-0.18BKT ceramics increased with the addition of La2O3doping. The electrical properties of 0.82BNT-0.18BKT ceramics have been greatly improved by certain amount of La2O3substitutions. At room temperature, the 0.82BNT-0.18BKT ceramics doped with 0.25 wt. % La2O3exhibited the optimum properties with high piezoelectric constant (d33= 142 pC/N) and high planar coupling factor (kp= 0.23).

Mechanism of Ca-Ba diffusion in lead-free (Ba,Ca)TiO3 piezoelectrics

2015 ◽  
Vol 1782 ◽  
pp. 23-28 ◽  
Author(s):  
Chang Shu ◽  
Daniel Reed ◽  
Tim Button
Keyword(s):  
Thermal Analysis ◽  
Reaction Mechanism ◽  
Solid State ◽  
Diffusion Couple ◽  
Grain Boundaries ◽  
Room Temperature ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe reaction mechanism of BaCO3+CaCO3+TiO2 by solid state methods has been studied in this work using thermal analysis (DSC-TG) from 500 to 1500 °C and in situ X-ray diffraction (XRD) from room temperature to 800 °C. In the mixed powders, the CaO is firstly formed followed by presence of an intermediate Ba2TiO4 phase and finally the formation of CaTiO3, BaTiO3 and/or (Ba,Ca)TiO3, where the presence of CaO or CaTiO3 (CT) has slowed down the formation of BaTiO3 (BT). Raman microscopy of a BT-CT diffusion couple has shown that Ca2+ firstly diffuses into the BT grain boundaries and then into the BT core.

Dielectric and Piezoelectric Properties of Na0.42K0.08Bi0.5 TiO3 and Na0.45K0.05Bi0.5TiO3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 251-254 ◽  
Author(s):  
Su Chuan Zhao ◽  
Lina Zhang ◽  
Guo Rong Li ◽  
Liao Ying Zheng ◽  
Ai Li Ding
Keyword(s):  
Room Temperature ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
X Ray Diffraction ◽  
Depolarization Temperature ◽  
X Ray ◽  
Single Perovskite Phase ◽  
Dielectric And Piezoelectric Properties ◽  
Rhombohedral Symmetry ◽  
Ferroelectric And Piezoelectric Properties

Na0.42K0.08Bi0.5TiO3 and Na0.45K0.05Bi0.5TiO3 ceramics were fabricated by the solid-state reaction. The structures were determined by X-ray diffraction. Dielectric, ferroelectric and piezoelectric properties of the ceramics were measured and discussed. The ceramics have a single perovskite phase with rhombohedral symmetry at room temperature. The thermal variations of the permittivity follow the law 1/ e − 1/ em = C(T − Tm)2 which is the character of typical relax ferroelectrics, when temperature is higher than the temperature of the maximum of dielectric constant (Tm). The depolarization temperature (Td) of spontaneous polarization is 215oC for Na0.45K0.05Bi0.5TiO3 and 152oC for Na0.42K0.08Bi0.5TiO3 respectively. There exist two different dielectric behaviors of the Na0.42K0.08Bi0.5TiO3 ceramic, without and after poling. Na0.45K0.05Bi0.5TiO3 possesses relatively high kt and Td. The use for device application has been indicated.

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