Phase Structure, Microstructure and Electrical Properties of Lead-Free (1-x) [Na0.515K0.485]0.94Li0.06(Nb0.99Ta0.01)O3 - BiAlO3 Ceramics

2013 ◽  
Vol 747 ◽  
pp. 781-784 ◽  
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Phase Structure ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Lead Free ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties

Lead-free (1-x)[(Na0.515K0.485)0.94Li0.06(Nb0.99Ta0.01)O3]-xBiAlO3 (NKLNT-BA; x = 0, 0.005, 0.010, 0.015, and 0.020) ceramics were fabricated by a conventional mixed-oxide method. The effects of BiAlO3 addition on the phase structure, microstructure and electrical properties of ceramic were then studied. The result indicated that grain size decreased with increasing of BiAlO3 content. In the composition range studied, the perovskite phase with the coexistence of the orthorhombic and tetragonal phases was identified at approximately x 0.005 by the X-ray diffraction analysis and dielectric spectroscopy, which led to a significant enhancement of the piezoelectric properties. The tetragonality increased with further increasing x. The temperature dependence of dielectric properties showed that the addition of BiAlO3 slightly decreased the ferroelectric tetragonal-paraelectric cubic phase transition temperature (TC), but greatly shifted the polymorphic phase transition from the ferroelectric orthorhombic to the ferroelectric tetragonal phase (TOT) to lower room temperature. The dielectric and piezoelectric properties are enhanced for the composition near the orthorhombic-tetragonal polymorphic phase boundary. The unmodified-(Na0.515K0.485)0.94Li0.06(Nb0.99Ta0.01)O3 ceramics exhibit optimum electrical properties (d33 = 225 pC/N and TC = 418°C).

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 LiNbO3 on Piezoelectric Properties of K0.5Na0.5NbO3 Ceramics

2010 ◽  
Vol 654-656 ◽  
pp. 2037-2040
Author(s):  
Ming He Cao ◽  
Zhuo Li ◽  
Fan Li ◽  
Hua Hao ◽  
Han Xing Liu
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Electrical Properties ◽  
Phase Structure ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Polymorphic Phase Transition ◽  
State Process

Lead-free (1-x)K0.5Na0.5NbO3–xLiNbO3 piezoelectric ceramics have been prepared by a conventional solid state process. The phase structure and the electrical properties of the ceramics were studied. A polymorphic phase transition (PPT) between the orthorhombic and tetragonal phases was identified in the composition range of 0.08<x<0.10. The ceramics near the PPT show better piezoelectric properties. At a level of 10mol% LiNbO3, the sample sintered at 1100oC for 1h exhibits optimal piezoelectric properties.

Dielectric and Piezoelectric Properties of Lead Free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 Piezoelectric Ceramics

2011 ◽  
Vol 492 ◽  
pp. 194-197 ◽  
Author(s):  
Yue Fang Wang ◽  
Xiu Jie Yi ◽  
Wei Pan ◽  
Guo Zhong Zang ◽  
Juan Du
Keyword(s):  
Electrical Properties ◽  
Dielectric Loss ◽  
Phase Structure ◽  
Perovskite Structure ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Compositional Dependence ◽  
Pure Perovskite Structure ◽  
Dielectric And Piezoelectric Properties

Lead-free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 ceramics were synthesized by ordinary sintering technique. The compositional dependence of phase structure and electrical properties of the ceramics was systematically investigated. All samples possessed pure perovskite structure. The dielectric and piezoelectric properties of ceramics were investigated with the amount of different BiFeO3 substitutions. The addition of BiFeO3 can not only decrease Ec and Pr but also lead to a significant degradation of the dielectric loss tanδ.

Chemical Composition of Dielectric and Piezoelectric Properties for BaTiO3-Bi (Mg1/2Ti1/2)O3-BiFeO3 System Ceramics

2013 ◽  
Vol 582 ◽  
pp. 84-87 ◽  
Author(s):  
Ryuta Mitsui ◽  
Ichiro Fujii ◽  
Kouichi Nakashima ◽  
Nobuhiro Kumada ◽  
Yoshihiro Kuroiwa ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Curie Temperature ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Rhombohedral Phase ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Dielectric And Piezoelectric Properties

1-x-y)BaTiO3-xBi (Mg1/2Ti1/2)O3-yBiFeO3 ceramics were prepared by a conventional solidstate synthesis, and crystal structure and electric properties were investigated. Synchrotron X-ray diffraction pattern revealed that a single perovskite phase was obtained for samples at x=0.05-0.15, y=0.46.5-73.5. Splitting of the (111) peak was observed when (x, y) = (0.050, 0.685) and (0.050, 0.735) indicating that crystal structure of samples changed from a pseudo-cubic phase to a rhombohedral phase with increasing BF. As the BF content increased, the Curie temperature increased. The largest maximum strain (Smax) over the applied maximum electric field (Emax) value (Smax / Emax) of 300 pm/V was observed for 0.365BT-0.050BMT-0.585BF at 25 °C and 1Hz with the Curie temperature of 390 °C.

Two-Step Sintering, Microstructure and Electrical Properties of (Ba, Ca)(Ti, Zr)O3 Lead-Free Ceramics

2015 ◽  
Vol 749 ◽  
pp. 79-83
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Electrical Properties ◽  
Piezoelectric Properties ◽  
Orthorhombic Phase ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Average Grain Size ◽  
Sintering Method ◽  
Dielectric And Piezoelectric Properties

In this work, the (Ba1-xCax)(Ti1-yZry)O3 lead-free ceramics were prepared by the two-step sintering method, and effects of Ca and Zr contents on phase structure, densification, microstructure, and electrical properties were investigated. It was found that all samples showed orthorhombic phase. The highest density of 5.84 ± 0.01 g/cm3 was achieved in x = 0.05, y = 0.05 sample. The average grain size, phase transition temperature, dielectric and piezoelectric properties significantly decreased by introducing of the Ca/Zr content. The ceramics with a small amount of Ca and Zr maintain good piezoelectric properties, and a lower dielectric loss. The composition with x = 0.05, y = 0.025 demonstrated optimum electrical properties of d33 ∼211 pC/N, TC ∼ 119 °C, εr ∼ 1788, and tanδ ∼ 0.04.

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.

scholarly journals Effects of sintering temperature on structure and electrical properties of (Na0.48k0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 piezoelectric ceramics

2021 ◽  
Vol 15 (1) ◽  
pp. 79-86
Author(s):  
Cheng-Shong Hong ◽  
Yi-Tian Hong
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Diffuse Phase Transition ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Piezoelectric Ceramics ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties ◽  
Diffuse Phase

In this study, the effects of sintering temperature on microstructure, dielectric and piezoelectric properties are investigated for the non-stoichiometric (Na0.48K0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 (NKLNTSST) piezoelectric ceramics. The results suggest that the piezoelectric properties are enhanced owing to the more normal ferroelectric characteristics, higher density, more uniform grains and presence of polymorphic phase transition regions, which are observed with an increase in the sintering temperature up to 1080?C. The piezoelectric properties are weakened owing to the larger degree of diffuse phase transition and more cationoxygen-vacancy pairs with an increase in the sintering temperature above 1080?C. The best piezoelectric properties including kp = 40%, d33 = 288 pC/N, ?max = 72.12, loss = 2.57%, Ec = 13.45 kV/cm and Pr = 10.23 ?C/cm2 are obtained at the sintering temperature of 1080?C.

Effects of NaNbO3 Crystals on Electrical Properties of K0.5Na0.5NbO3 Ceramics

2016 ◽  
Vol 690 ◽  
pp. 126-130 ◽  
Author(s):  
Chavalit Suksri ◽  
Piewpan Parjansri ◽  
Sutatip Thonglem ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Seed Crystal ◽  
Molten Salt Synthesis ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Structure And Morphology ◽  
Pure Perovskite Phase

Lead-free (K0.5Na0.5)NbO3 (KNN) piezoelectric ceramics were studied and synthesized by the seed-induced method. NaNbO3 crystal was used as seed and prepared by molten salt synthesis (MSS). The average particles size of NaNbO3 seed crystal was about 1-3 mm. Then, the NaNbO3 seed was mixed with KNN powder and ball milled for 24 h. The mixed powder was calcined at 700-900 °C and sintered at 1100 °C. The phase structure and morphology of the ceramics were investigated by X-ray diffraction and scanning electron microscope and the electrical properties were studied. The results indicated that all samples showed a pure perovskite phase. The highest density of the ceramic was 93% compared to the theoretical density. The results showed that NaNbO3seed crystal improved piezoelectric properties of KNN ceramics.

Sign in / Sign up

Export Citation Format

Share Document