Piezoelectric and Ferroelectric Properties of KNbO3 Added Bi0.5Na0.5TiO3 Ceramics

2017 ◽  
Vol 751 ◽  
pp. 384-389 ◽  
Author(s):  
Puripat Kantha ◽  
Phathaitep Raksa ◽  
Muangjai Unruan ◽  
Tawee Tunkasiri ◽  
Panupong Jaiban ◽  
...  

The fabrication of lead-free (1-x)Bi0.5Na0.5TiO3 - xKNbO3 or (1-x)BNT-xKN ceramics where x = 0.00, 0.05, 0.10, and 0.15 was carried out by the modified two-step mixed oxide method. The effects of KNbO3 on structure, piezoelectric and ferroelectric properties were systematically investigated. XRD results revealed that the (1-x)BNT-xKN ceramics with low KN content of x less than 0.05 contained ferroelectric phase with a rhombohedral symmetry while the ceramics with x = 0.05 possessed pseudocubic structure. The higher KN content (x ≥ 0.10) ceramics had symmetries rhombohedral structure. At room temperature, the highest Pr and low Ec were obtained when the composition of x = 0.05. Moreover, the results showed the moderate KN addition could enhance the piezoelectric response. The d33 of 0.95BNT-0.05KN reached as high as 125 pC/N.

2015 ◽  
Vol 830-831 ◽  
pp. 620-623 ◽  
Author(s):  
Kusum Parmar ◽  
Hakikat Sharma ◽  
Sarita Sharma ◽  
N.S. Negi

Lead Free Ferroelectric Na0.5Bi0.5TiO3 (NBT) Ceramic has been synthesized using sol gel method. The prepared NBT samples have been sintered at different temperatures 850°C, 950°C, 1050°C and 1150°C to achieve best sintering temperature. Structural analyses have been carried out using XRD and FTIR measurements. XRD patterns confirm perovskite structure having rhombohedral symmetry for all samples which is also supported by characteristic absorption band at ~627cm-1 in FTIR spectra. Dielectric properties of NBT samples with frequency and temperature have been studied. NBT sample sintered at 1050°C exhibit comparatively high value of dielectric constant (ε’) and phase transition temperature (Tm). Ferroelectric properties of NBT samples have been studied at room temperature. Comparatively, better ferroelectric properties are observed for NBT sample having remnant polarization (Pr)~ 14.7 μC/cm2and coercive field (Ec)~ 26.8 kV/cm sintered at 1050°C.


2019 ◽  
Vol 09 (03) ◽  
pp. 1950022 ◽  
Author(s):  
Zhi-Hao Zhao ◽  
Rui-Fang Ge ◽  
Yejing Dai

This paper investigates a system of 0.93[Formula: see text][Formula: see text]TiO3–0.06BaTiO3–0.01[Formula: see text][Formula: see text]NbO3–[Formula: see text]CuO (BNT–BT–KNN–[Formula: see text]CuO, [Formula: see text][Formula: see text]mol.%) ceramics, which were fabricated by the conventional solid-state process through the granulation of vacuum freeze drier. The results show that the CuO doping made a significant enhancement on the piezoelectric properties of the BNT–BT–KNN ceramics. With the doping of CuO, the transition temperature between ferroelectric phase and ergodic relaxor state is reduced to near room temperature, resulting in pinched [Formula: see text]–[Formula: see text] loops and “sprout” shape [Formula: see text]–[Formula: see text] curves. For the composition with [Formula: see text], a high unipolar strain of 0.39% under 5[Formula: see text]kV/mm contributes a large [Formula: see text][Formula: see text]pm/V at room temperature, which is competitive with the other BNT-based ceramics.


Author(s):  
Zheng Tang ◽  
Xiaofan Sun ◽  
Zhangran Gao ◽  
Dong Li ◽  
Shulin Jiao ◽  
...  

Organic-inorganic hybrid ferroelectric Tris(2-Hydroxyethyl) ammonium trichloro cadmium(Ⅱ) (TATC) with a space group of P21/c at room temperature was obtained in aqueous solution. There goes a paraelectric-ferroelectric phase transition (from monoclinic...


2013 ◽  
Vol 634-638 ◽  
pp. 2345-2348 ◽  
Author(s):  
Hong Mei Zhang ◽  
Shao Bo Qu ◽  
Jing Bo Zhao ◽  
Hong Liang Du

(1-X)K0.5Na0.5NbO3–xBiGaO3[(1-X)KNN-Xbg] Lead-Free Ceramics with Different Additive of Bigao3 Were Synthesized by Conventional Solid-State Sintering Technique. Dielectric, Piezoelectric and Ferroelectric Properties of (1-X)KNN-Xbg Lead-Free Ceramics Were Studied. it Is Found that the Piezoelectric Properties Was Improved due to the Additive Bigao3,The Ceramics X=0.01 near Room Temperature Exhibit Excellent Electrical Properties D33=152pC/N, TC=372 °C. these Results Indicate that Bigao3 Adjusted K0.5Na0.5NbO3-Based Ceramics Materials Are Promising Lead-Free Piezoelectric Ceramic Candidates for Practical Applications.


2021 ◽  
Author(s):  
Abdelrazek Mahmoud ◽  
Samar Moen ◽  
M.K. Gerges

Abstract In the present work, a series compositions of (Ba1-xSrx)TiO3 (0≤x≤0.4) lead-free ferroelectric (BST) were successfully prepared by sol-gel method. The effects of Sr2+ on the optical properties, crystal structure and morphology of BaTiO3 were systematically investigated. Compositions with x<0.4 exhibit single phase tetragonal perovskite at room temperature, while a cubic structure of BST has been detected in the ceramic with x=0.4. Phase transition temperature was shifted toward lower temperature by increasing Sr-doping. Moreover, detailed tunability analysis for the present ceramics confirmed an enhancement by Sr-addition and the maximum values were observed at Sr=0.2. The enhancement back to present multiple components contribute to the dc-field induced dielectric constant, where at low electric fields the Langevin theory indicate present polar nano-region (PNR) contributions into tunability data, however domain switching contributions at high electric field was described by Johnson equation. Ferroelectric properties appraised by P-E loop and positive up negative down (PUND) methods have been introduced. The results shown the remnant polarization appraised by PUND method is much lower than polarization estimated by P-E loop indicate the difference values of Pr is mostly owing to leakage current contribution in P-E method.


2018 ◽  
Vol 777 ◽  
pp. 55-59 ◽  
Author(s):  
Pharatree Jaita ◽  
Supalak Manotham ◽  
Narumon Lertcumfu

In this research, the effects of sintering temperature on phase structure, densification, microstructure, and electrical properties of modified-BNKT ceramics were investigated. Conventional sintering of lead-free 0.97Bi0.5(Na0.80K0.20)0.5TiO3-0.03(Ba0.70Sr0.30)O3or 0.97BNKT-0.03BSrT ceramic was investigated to clarify the optimal sintering temperature for densification and electrical properties. All ceramics were prepared by a conventional mixed oxide and sintered at various temperatures from 1100 to 1150°C. XRD pattern indicated all ceramics exhibited a single perovskite without any secondary phases. The maximum density of 5.80 g/cm3with relative density of 99.32% were observed for the ceramic sintered at 1125°C. Grain size tended to increase with increasing the sintering temperature. The good dielectric (Td= 121 °C, Tm= 320 °C and e¢max= 4982) and ferroelectric properties (Pr= 16.66 µC/cm2, Ec= 17.85 kV/cm and Rsq= 0.74) were obtained for the ceramic sintered at optimum sintering temperature of 1125°C.


Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 129
Author(s):  
Qian Wang ◽  
Hong-Ze Yan ◽  
Xian Zhao ◽  
Chun-Ming Wang

BaTiO3-based piezoelectric ceramics have attracted considerable attention in recent years due to their tunable phase structures and good piezoelectric properties. In this work, the (1 − x)BaTiO3−xCaSnO3 (0.00 ≤ x ≤ 0.16, abbreviated as BT−xCS) solid solutions, were prepared by traditional solid-state reaction methods. The phase transitions, microstructure, dielectric, piezoelectric, and ferroelectric properties of BT-xCS have been investigated in detail. The coexistence of rhombohedral, orthorhombic, and tetragonal phases near room temperature, i.e., polymorphic phase transition (PPT), has been confirmed by X-ray diffraction and temperature-dependent dielectric measurements in the compositions range of 0.06 ≤ x ≤ 0.10. The multiphase coexistence near room temperature provides more spontaneous polarization vectors and facilitates the process of polarization rotation and extension by an external electric field, which is conducive to the enhancement of piezoelectric response. Remarkably, the composition of BT-0.08CS exhibits optimized piezoelectric properties with a piezoelectric coefficient d33 of 620 pC/N, electromechanical coupling factors kp of 58%, kt of 40%, and a piezoelectric strain coefficient d33* of 950 pm/V.


2020 ◽  
Author(s):  
R. López-Noda ◽  
J. Portelles ◽  
G. Rojas-George ◽  
A. Reyes-Rojas ◽  
J. Fuentes ◽  
...  

Abstract (K0.44Na0.52Li0.04)0.97La0.01Nb0.9Ta0.1O3 lead free ceramics were synthesized by sol-gel method. Their morphology, crystal structure and spectroscopic dielectric properties were analyzed by the appropriate techniques. The co-existence of an orthorhombic and a tetragonal ferroelectric phase at room temperature is confirmed by Rietveld analysis. La and Li cations are effective in shifting down the ferroelectric transition temperatures. The tetragonal to cubic transition, (TT-C), takes place at 371 °C while the orthorhombic to tetragonal, (TO-T), occurs at 110 °C, and the maximum relative permittivity (ɛmax) at TT-C is 3000, which is among the highest for KNN-based ceramics obtained by different methods. Conductivity behaves according to Jonscher’s law in the frequency and temperature range of this study. The activation energy values corresponding to the different conduction mechanisms were obtained. The results were compared with those for the same composition obtained by combining the reactive template grain growth (RTGG) technique and the solid-state method.


2017 ◽  
Vol 863 ◽  
pp. 8-14
Author(s):  
Yu Chen Guo ◽  
Hui Qing Fan ◽  
Jing Shi

The perovskite oxide Bi0.5Na0.5MnxTi1-xO3, Bi0.5Na0.5NbxTi1-xO3, Bi0.5Na0.5 (Mn0.5Nb0.5)xTi1-xO3 and Bi0.5Na0.5TiO3 ceramics (x=0.25%) were prepared via the conventional solid state reaction method. The role of Mn as an acceptor, Nb as a donor and (Mn0.5Nb0.5) substitution at B site in BNT lead-free piezoceramics was investigated. The (Mn0.5Nb0.5) substitution led to the inhibited of reduction of Ti4+ to Ti3+ and gave rise to large defect-dipole clusters containing highly localized electrons which should be responsible for the increase of Tc and Td. The ferroelectric properties and field-induced strains were both improved by Mn-acceptor and (Mn0.5Nb0.5) co-doped. The fatigue-resistant properties of Nb doped BNT ceramics were comparable to BNT ceramics, Mn doped ceramics were found to have significantly improved fatigue-resistant properties, while almost no profound fatigue was observed in BNT-MnNb ceramics after switching over 106 cycles at room temperature.


2021 ◽  
Vol 33 (3) ◽  
pp. 665-670
Author(s):  
M. Ahabboud ◽  
T. Lamcharfi ◽  
F. Abdi ◽  
N. Hadi ◽  
F.Z. Ajyaje ◽  
...  

In present work, the structural and dielectric properties of Pb1-xCuxZr0.52Ti0.48O3 (PCxZT) ceramics where x = 0. 0.025, 0.05, 0.075, 0.10, 0.15 and 0.20 were studied. Powder of the compositions (PCxZT) was obtained by sol-gel route, the powders were calcined at 700 ºC for 4 h and sintered at 1100 ºC for 4 h. X-ray diffraction analysis and Raman spectroscopy suggest the formation of mixed-phase of tetragonal and rhombohedral structure which was confirmed by Rietveld refinement. Dielectric measurements of the compounds were studied as a function of temperature (from room temperature to 420 ºC at different frequencies) and as a function of frequency (from 100 Hz to 2 MHz at different temperatures). The temperature variation of the real permittivity gives evidence of the ferroelectric phase transition as well as of the resonance behaviour also observed in the dielectric permittivity frequency-dependent variation.


Sign in / Sign up

Export Citation Format

Share Document