Effects of Dwell Time Sintering on Microstructure, Piezoelectric and Mechanical Properties of Modified BNT-Based Ceramics

2016 ◽  
Vol 675-676 ◽  
pp. 544-547
Author(s):  
Supalak Manotham ◽  
Thanatep Phatungthane ◽  
Tawee Tunkasiri ◽  
Komsanti Chokethawat
Keyword(s):  
Mechanical Properties ◽  
Dwell Time ◽  
Perovskite Phase ◽  
Microstructural Analysis ◽  
Lead Free ◽  
Ceramic Samples ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Sintering Method ◽  
Rhombohedral Symmetry

The properties of modified Bi0.5Na0.5TiO3 (BNT) based lead-free ceramics were investigated. The BNT-based ceramics were prepared by a two-steps sintering method. The ceramics were sintered at T1=1373 K and T2= 1173 K for various dwell times (0, 2, 4, and 8h). The properties of the ceramics were characterized by many techniques. The ceramic samples exhibited a pure perovskite phase with rhombohedral symmetry. The microstructural analysis by a scanning electron microscopy (SEM), indicated that all ceramics had a similar microstructure. Piezoelectric and mechanical properties of the ceramics were improved at a suitable dwell time at T2.

scholarly journals Microstructural and Electrical Properties of Sn-Modified BaTiO3 Lead-Free Ceramics by Two-Step Sintering Method

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Wichita Kayaphan ◽  
Pornsuda Bomlai
Keyword(s):  
Electrical Properties ◽  
Curie Temperature ◽  
Dwell Time ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Lead Free ◽  
Tetragonal Symmetry ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Structural And Electrical Properties

Ba(Ti0.92Sn0.08)O3 lead-free ceramics were prepared using a two-step sintering (TSS) technique. Varying the first sintering temperature T1 (1400 and 1500°C) and the dwell time t1 (0, 15, and 30 min), we obtained dense ceramics which were then soaked at a constant temperature of 1000°C (T2) for 6 h (t2). The structural and electrical properties were investigated. XRD results indicated that all the ceramics showed a pure perovskite phase with tetragonal symmetry. Density and grain size increased with higher T1 temperatures and increased t1 dwell times. Enhanced electrical properties were achieved by sintering at the optimized T1 sintering temperature and t1 dwelling time. At the lower T1 sintering temperature of 1400°C, the dielectric and piezoelectric properties and the Curie temperature of the ceramics were improved significantly by increasing t1 dwell time. Further, increasing the sintering temperature T1 to 1500°C, excellent properties were obtained at t1 = 15 min which then deteriorated when t1 was increased to 30 min. The electrical properties of the sample sintered under the T1/t1/T2/t2 condition of “1500/15/1000/6” showed the best values. For this sample the piezoelectric coefficient (d33), dielectric permittivity (εr), loss factor (tanδ), and Curie temperature (TC) were 490 pC/N, 4385, 0.0272, and 48°C, respectively.

Piezoelectric and Strain Properties of Strontium-Doped BZT-BCT Lead-Free Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1385-1389 ◽  
Author(s):  
Wang Feng Bai ◽  
Wei Li ◽  
Bo Shen ◽  
Ji Wei Zhai
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Electromechanical Coupling Coefficient ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Free Material

Lead-free piezoelectric ceramics, (Ba0.85-xSrxCa0.15)(Zr0.1Ti0.9)O3 (BSCZT, x=0.01-0.07), were prepared via a solid-state reaction route. The dielectric properties, ferroelectric properties, piezoelectric and strain properties of BSCZT ceramics were studied. The phase structure and microstructure were investigated by X-ray diffraction and scanning electron microscope, respectively. Results showed that dense ceramics with pure perovskite phase were obtained. At room temperature, the samples with x=0.03 exhibited excellent properties with large piezoelectric coefficient d33=534pC/N, planar mode electromechanical coupling coefficient kp=47.7%, thickness mode electromechanical coupling coefficient kt= 42% and high strain levels of 0.34%. In addition, the study of electrical properties suggested that the Curie temperature decreased linearly from 92oc to 73oc with the increasing doping content of strontium in BCZT ceramics. The remnant polarizations, piezoelectric coefficient and strain levels were all increased as the Sr content increased and then decreased with further increased Sr doping level, giving the maximum values at the Sr content of 3mol%. These results indicated that the BSCZT system is a promising lead-free material for applications in the future.

scholarly journals Structural, microstructural and dielectric characterizations of (Bi0.5Na0.5)TiO3based lead-free ferroelectric ceramics

2021 ◽  
pp. 2140006
Author(s):  
B. R. Moya ◽  
A. C. Silva ◽  
A. Peláiz-Barranco ◽  
J. D. S. Guerra
Keyword(s):  
Lead Free ◽  
Ferroelectric Ceramics ◽  
Reaction Sintering ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Porosity Level ◽  
X Ray ◽  
Ceramic Samples ◽  
Lead Free Ceramics ◽  
Sintering Method

(1–[Formula: see text]Bi[Formula: see text]Na[Formula: see text]TiO3–[Formula: see text]BaTiO3 lead-free ceramics have been obtained from the conventional solid-state reaction sintering method. The structural properties were investigated from X-ray diffraction and Raman spectroscopy techniques. Results revealed well-crystallized ceramic samples with perovskite structure. Microstructural properties, obtained from scanning electron microscopy measurements, have shown high density with very low porosity level. The dielectric response, analyzed as a function of the temperature and several frequencies, showed very broad peaks with a strong frequency dependence of the temperature for the maximum dielectric permittivity for the modified system. Results were analyzed considering the influence of the BaTiO3 content on the studied physical properties.

Electrocaloric properties of Sr and Sn doped BCZT lead-free ceramics

2020 ◽  
Vol 91 (2) ◽  
pp. 20905
Author(s):  
Satyanarayan Patel ◽  
Manish Kumar
Keyword(s):  
Electric Fields ◽  
Perovskite Phase ◽  
Entropy Change ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Sn Doping ◽  
Adiabatic Temperature Change ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase

In the present work, the electrocaloric (EC) effect in lead-free Sr and Sn doped (Ba0.85Ca0.075Sr0.075)(Zr0.1Ti0.88Sn0.02)O3 ceramic prepared by solid-state method has been investigated. The phase purity and pure perovskite phase formation with Sr and Sn doping is confirmed by X-ray diffraction. The adiabatic temperature change ΔT (due to the EC effect), entropy change (ΔS) and refrigeration capacity (RC) are estimated under various electric fields. The maximum peak values of ΔT, ΔS and RC are found as 1.5 K, 1.8 J/kg.K and 2.75 J/kg, respectively under the applied electric field of 33 kV/cm at 305 K. It is also observed that the ΔT, ΔS and RC decreases with an increase in applied temperature. Moreover, the estimated values of EC properties are significantly high which indicates that fabrication of Sr and Sn doped lead-free ceramics can be advantageous for EC applications.

MICROSTRUCTURES AND PIEZOELECTRIC PROPERTIES OF KNNLST DOPING BCZT LEAD-FREE CERAMICS

2012 ◽  
Vol 05 (04) ◽  
pp. 1250041 ◽  
Author(s):  
WEI XU ◽  
YANG LI ◽  
JIAN-MIN FENG ◽  
YE-JING DAI
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Piezoelectric Behavior

In this study, lead-free piezoelectric ceramics ( Na0.52K0.44Li0.04 )( Nb0.88Sb0.08Ta0.04 ) O3 -doped 0.52 Ba ( Zr 0.2 Ti 0.8) O 3-0.48( Ba 0.7 Ca 0.3) TiO 3( BCZT -x KNNLST ) are investigated. The effects of the KNNLST addition on the microstructures and the electrical properties of the ceramics sintered at the temperature as low as 1350°C are studied. The X-ray diffraction data show that the addition of KNNLST could diffuse into BCZT lattice and a pure perovskite phase is formed. With the increase of KNNLST addition, the average grain size is first increased and afterwards decreased. The ceramics with x = 0.005 exhibit a good piezoelectric behavior of d 33 ~ 464 pC/N and k p ~ 0.44 after three month's aging, which indicates the BCZT -x KNNLST ceramics could be promising for lead-free practical applications.

Ferroelectric Properties of Sn-Doped PZT–PNN Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 933-936
Author(s):  
Krit Sutjarittangtham ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam ◽  
Gobwute Rujijanagul
Keyword(s):  
Grain Size ◽  
Binary System ◽  
Remanent Polarization ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Microstructural Analysis ◽  
X Ray ◽  
Sn Doping ◽  
Ceramic Samples ◽  
Pure Perovskite Phase

Binary system of 0.45Pb(Zr1/2Ti1/2)O3–0.55Pb(Ni1/3Nb2/3)O3with a composition close to the morphotropic phase boundary were investigated as a function of Sn doping (0.0-8.0 mole%). X-ray analysis showed that pure perovskite phase was observed for all samples. The density of the ceramic samples was increased with an increase of Sn concentration. However, microstructural analysis showed that Sn-doping has not a significant impact on grain size. Moreover, the increasing Sn-contant can reduce the remanent polarization but increase the dielectic contant.

scholarly journals Structural, Dielectric and Ferroelectric Properties of Cu2+ and Cu2+/Bi3+ doped BCZT Lead-free Ceramics: A Comparative Study

2021 ◽  
Author(s):  
Sapna Kumari ◽  
Amit Kumar ◽  
V. Kumar ◽  
S. K. Dubey ◽  
P. K. Goyal ◽  
...  
Keyword(s):  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Physical Mechanisms ◽  
A Value ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase ◽  
Perovskite Type

Abstract Perovskite type Ba0.98Ca0.02Zr0.02Ti0.98O3 (BCZT), Ba0.98Ca0.02Zr0.02Ti0.976Cu0.008O3 (BCZTC) and Ba0.9725Bi0.005Ca0.02Zr0.02Ti0.976Cu0.008O3 (BCZTCB) lead-free ceramics were synthesised via solid-state reaction method at a sintering temperature of ~ 1380°C. Effects of CuO and Bi2O3/CuO doping on structural, microstructural, dielectric, and ferroelectric properties were investigated systematically. X-ray diffraction technique confirmed the existence of pure perovskite phase with the tetragonal structure in pure and in the doped BCZT ceramics at room temperature. The dielectric analysis demonstrated two anomalies around 24°C and 126°C for BCZT, which were identified as orthorhombic to tetragonal (TO-T) and tetragonal to cubic (TC) phase transition temperature, respectively. The TO-T temperature shifted to below 16°C, while the TC increased to 132°C for the BCZTCB sample. The physical mechanisms of the conduction processes were investigated through impedance spectroscopy and the values of resistance, conductivity, and activation energies associated with the grain and grain boundaries were evaluated. The activation energy was determined to be higher for doped samples than for pure BCZT. Further, the dopant-dependent ferroelectric nature of the ceramic samples was evidenced by the analysis of characteristic hysteresis loop, and a value of remnant polarisation (Pr = 4.59 µC/cm2) was obtained for the BCZTCB ceramic sample. Furthermore, the d33 value, which was 54 pC/N for pure BCZT, was determined to be 140 pC/N and 64 pC/N for BCZTC and BCZTCB, respectively.

The Research on the Piezoelectric and Dielectric Properties of Bi0.5(Nak)0.5-BaTiO3 Lead-Free Ceramics

2014 ◽  
Vol 1035 ◽  
pp. 422-425
Author(s):  
Jian Yong Guo ◽  
Tao Sheng Zhou ◽  
Ji Hong Liao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Lead Free ◽  
Reactive Sintering ◽  
Lead Free Ceramics ◽  
Xrd Patterns ◽  
Sintering Method

The Bi0.5(Na1-xKx)0.5-yBaTiO3(BNK-BT) lead-free ceramics have been prepared by the solild reactive sintering method. XRD patterns show the BNK-BT ceramics had a perovskite structure. Piezoelectric and dielectric properties of the ceramics also have been studied. The results show that the samples had the best piezoelectric and dielectric properties when x=0.20, y=0.10. And the maximum of d33is 149 pC/N, while the relative dielectric constant is 1087.

High Piezoelectric Properties and High TC in KNN-Based Lead-Free Ceramics Sintered in Reducing Atmosphere

2018 ◽  
Vol 281 ◽  
pp. 628-633
Author(s):  
Yi Chao Zhen ◽  
Zhen Yong Cen ◽  
Wei Feng ◽  
Xiao Hui Wang ◽  
Long Tu Li
Keyword(s):  
Piezoelectric Properties ◽  
Rhombohedral Phase ◽  
Lead Free ◽  
Reducing Atmosphere ◽  
Lead Free Ceramics ◽  
Commercial Applications ◽  
T Phase ◽  
Sintering Method ◽  
Mn Doped ◽  
Piezoelectric Constants

Lead-free MnO doped 0.955K0.5Na0.5NbO3-0.045Bi0.5Na0.5ZrO3(abbreviate as KNN-0.045BNZ) ceramics have been prepared by a conventional solid-state sintering method in a reducing atmosphere. The addition of MnO suppresses grain growth and eliminates the liquid phase. MnO dopant changes the crystalline structures of KNN-0.045BNZ ceramics from the classical Morphotropic Phase Boundary (MPB) with rhombohedral phase (R) and tetragonal phase (T) to the suppressed MPB with R/T phase. The 0.4% MnO doped KNN-0.045BNZ ceramics show an excellent electrical properties with quasi static piezoelectric constantd33=300 pC/N, Curie temperatureTC= 350 °C, insulation resistivity ρ=4.83 × 1011(Ω・cm), and high field piezoelectric constants =438 pm/V (atEmax= 25 kV/cm). The results indicate that the 0.4%Mn doped KNN-0.045BNZ ceramic is a promising lead-free piezoelectric candidate material for commercial applications.

Physical and Mechanical Properties of Bi0.5(Na0.81K0.19)0.5TiO3 Ceramic Modified by KNbO3

2019 ◽  
Vol 805 ◽  
pp. 71-75
Author(s):  
Suchittra Inthong ◽  
Chatchai Kruae-In ◽  
Wuttikrai Thanomsiang ◽  
Suppanat Kosolwattana ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mixed Oxides ◽  
Perovskite Phase ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Ceramic Samples ◽  
Pure Phase ◽  
Knoop Microhardness

This research reports the physical and mechanical properties of (1-x) Bi0.5(Na0.81K0.19)0.5TiO3-xKNbO3 (x=0.00-0.06) ceramics. The Modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics were synthesized by solid state reaction technique. The mixed oxides powders were calcined at 850 °C, 4 h and sintered at 1120 °C, 2 h to form pure phase perovskite and the optimum bulk density, respectively. The phase formation of the modified ceramic samples was determined by X-ray diffraction technique. All of the modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics exhibited a single perovskite phase. The bulk densities of the modified ceramic samples were 5.41±0.27-5.75±0.28 g/cm3 using the Archimedes’ method. The microstructure was revealed by the scanning electron microscope. The rectangular-like shape was found of all studied ceramics which had the grain size between 1.31±0.02-1.56±0.03 mm. The mechanical properties were studied by both Vickers and Knoop microhardness tester. The results are discussed in term of the relation among hardness properties, Young’s modulus, and fracture toughness.

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