共查询到20条相似文献,搜索用时 46 毫秒
1.
S.H. Choy X.X. Wang C.P. Chong H.L.W. Chan P.C.K. Liu C.L. Choy 《Applied Physics A: Materials Science & Processing》2006,84(3):313-316
Lead-free piezoelectric ceramic 0.90(Bi1/2Na1/2)TiO3–0.05(Bi1/2K1/2)TiO3–0.05BaTiO3 (BNKBT-5) rings (OD=12.7 mm, ID=5.1 mm and 2.3-mm thick) were fabricated and characterized. Four ceramic rings were used as the driving element in an ultrasonic wirebonding transducer and the performance of the transducer was characterized. The lead-free transducer was found to have comparable voltage rise and fall times as a lead-based PZT transducer and has a relatively large vibration amplitude, thus showing that BNKBT-5 has the potential to be used in fabricating lead-free ultrasonic wirebonding transducers. PACS 77.22.Ej; 77.84.-s; 85.50.-n 相似文献
2.
Lead-free (Bi0.98−x
La0.02Na1−x
)0.5Ba
x
TiO3 ceramics have been prepared by an ordinary sintering technique and their structure, ferroelectric and piezoelectric properties
have been studied. The results of X-ray diffraction show that La2+ and Ba2+ diffuse into the Bi0.5Na0.5TiO3 lattices to form a new solid solution with a pure perovskite structure, and a morphotropic phase boundary (MPB) exists at
0.04<x<0.10. Compared with pure Bi0.5Na0.5TiO3 ceramics, the (Bi0.98−x
La0.02Na1−x
)0.5Ba
x
TiO3 ceramics possess much smaller coercive field E
c and larger remanent polarization P
r. Because of the low E
c (3.38 kV/mm), large P
r (46.2 μC/cm2) and the formation of the MPB of rhombohedral and tetragonal phases, the piezoelectric properties of the ceramics are significantly
enhanced at x=0.06: d
33=181 pC/N and k
p=36.3%. The depolarization temperature T
d reaches a minimum value near the MPB. The ceramics exhibit relaxor characteristic, which is probably a result from the cation
disordering in the 12-fold coordination sites. The temperature dependences of the ferroelectric and dielectric properties
suggest that the ceramics may contain both polar and non-polar regions at the temperatures above T
d. 相似文献
3.
Chang Won AhnSung Sik Won Aman UllahSun Young Lee Su Dae LeeJi Hye Lee William JoIll Won Kim 《Current Applied Physics》2012,12(3):903-907
0.85Bi0.5Na0.5TiO3-0.15Bi0.5K0.5TiO3 (BNKT15) lead-free thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the chemical solution deposition method. BNKT15 are MPB composition in the Bi0.5Na0.5TiO3-Bi0.5K0.5TiO3 (BNT-BKT) system. The maximum piezoelectric coefficient (d33,f) value of BNKT15 thin film is approximately 75 pm/V, which is comparable to that of polycrystalline PZT thin films. These results suggest that BNKT15 thin film can be used as an alternative for PZT films in piezoelectric micro-electromechanical systems. 相似文献
4.
S.H. Choy X.X. Wang H.L.W. Chan C.L. Choy 《Applied Physics A: Materials Science & Processing》2007,89(3):775-781
Lead-free (0.90-x)(Bi1/2Na1/2)TiO3-0.05(Bi1/2K1/2)TiO3-x(Bi1/2Li1/2)TiO3-0.05BaTiO3 piezoelectric ceramics (abbreviated as BNKLBT-100x, with x ranged from 0 to 2.5 mol %) were prepared by a conventional mixed
oxide method. Effects of the amount of (Bi1/2Li1/2)TiO3 (BLT) on the electrical properties and crystal structure of the BNKLBT ceramics were examined. BNKLBT-1.5 ceramics have good
properties with piezoelectric constant d33=163 pC/N, electromechanical coupling factor kp=0.33, kt=0.53, relative permittivity εr=785 and dissipation factor cosδ=2.2% at 1 kHz. The sample has larger remnant polarization than BNKLBT-0 ceramics and the
same coercive field as BNKLBT-0 ceramics. X-ray diffraction analysis shows that the incorporated BLT diffuses into the BNT–BKT–BT
lattice to form a solid solution during sintering, but changes the crystal structure from rhombohedral to tetragonal symmetry
at higher BLT amounts. Depolarization temperature (Td) of the BNKLBT-100x ceramics increases from 102 °C to ∼136 °C for BNKLBT-0 to BNKLBT-2.5. BNKLBT-1.5 is used as the transduction
element in compressive type accelerometer and its sensitivity is calibrated by the back-to back method. Within the ±2.5% tolerance,
the lead-free accelerometer has a mean value of 2.97 pC/ms-2 within 50 Hz–12.45 kHz and the lead-based accelerometer has a mean value of 4.34 pC/ms-2 within 50 Hz to 8.24 kHz.
PACS 77.22.Ej; 77.84.-s; 85.50.-n 相似文献
5.
6.
S.H. Choy X.X. Wang H.L.W. Chan C.L. Choy 《Applied Physics A: Materials Science & Processing》2006,82(4):715-718
Lead-free piezoelectric 0.90(Bi1/2Na1/2)TiO3-0.05(Bi1/2K1/2)TiO3-0.05BaTiO3 ceramics(abbreviated as BNKBT-5) rings were fabricated using a conventional mixed oxide method. The ceramics have a piezoelectric
constant d33=168 pC/N, electromechanical coupling factors kp=0.313 and kt=0.487. The BNKBT lead-free ceramic rings were used as the transduction elements in a compressive type accelerometer and its
performance compared with a lead zirconate titanate (PZT) APC 840 ceramic accelerometer with similar structure. The lead-free
accelerometer shows good performance and has a broader frequency response compared to the lead-based PZT accelerometer.
PACS 77.22.Ej; 77.84.-s; 85.50.-n 相似文献
7.
Dunmin Lin Qiaoji Zheng Chenggang Xu K. W. Kwok 《Applied Physics A: Materials Science & Processing》2008,93(2):549-558
(1−x−y)Bi0.5Na0.5TiO3–xBi0.5K0.5TiO3– yBi0.5Li0.5TiO3 lead-free piezoelectric ceramics have been prepared by an ordinary sintering technique, and their structure, electrical properties,
and temperature characteristics have been studied systematically. The ceramics can be well-sintered at 1050–1150 °C. The increase
in K+ concentration decreases the grain-growth rate and promotes the formation of grains with a cubic shape, while the addition
of Li+ decreases greatly the sintering temperature and assists in the densification of BNT-based ceramics. The results of XRD diffraction
show that K+ and Li+ diffuse into the Bi0.5Na0.5TiO3 lattices to form a solid solution with a pure perovskite structure. As x increases from 0.05 to 0.50, the ceramics transform gradually from rhombohedral phase to tetragonal phase and consequently
a morphotropic phase boundary (MPB) is formed at 0.15≤x≤0.25. The concentration y of Li+ has no obvious influence on the crystal structure of the ceramics. Compared with pure Bi0.5Na0.5TiO3, the partial substitution of K+ and Li+ for Na+ lowers greatly the coercive field E
c and increases the remanent polarization P
r of the ceramics. Because of the MPB, lower E
c and large P
r, the piezoelectricity of the ceramics is improved significantly. For the ceramics with the compositions near the MPB (x=0.15–0.25 and y=0.05–0.10), the piezoelectric properties become optimum: piezoelectric coefficient d
33=147–231 pC/N and planar electromechanical coupling factor k
P=20.2–41.0%. In addition, the ceramics exhibit relaxor characteristic, which probably results from the cation disordering
in the 12-fold coordination sites. The depolarization temperature T
d shows a strong dependence on the concentration x of K+ and reaches the lowest values at the MPB. The temperature dependences of the ferroelectric and dielectric properties at high
temperatures may imply that the ceramics may contain both the polar and non-polar regions at temperatures above T
d. 相似文献
8.
Phase transition,dielectric and piezoelectric properties of NaNbO3–Bi0.5Li0.5TiO3 lead-free ceramics
Lingling Fu Dunmin Lin Qiaoji Zheng Xiaochun Wu Lang Wu Hailing Sun Yang Wan Ximing Fan Chenggang Xu 《Current Applied Physics》2012,12(6):1523-1528
Lead-free ceramics (1?x)NaNbO3–xBi0.5Li0.5TiO3 have been fabricated by an ordinary sintering technique, and their electric properties and temperature characteristics have been studied. All the ceramics possess a perovskite structure with orthorhombic symmetry, indicating that (Bi0.5Li0.5)TiO3 diffuses into NaNbO3 lattices to form a new solid solution. A low (Bi0.5Li0.5)TiO3 doping level transforms the NaNbO3 ceramics from antiferroelectric to ferroelectric. The ceramics with x ≤ 0.075 are normal ferroelectric, and the ferroelectric-paraelectric phase become diffusives with the doping level of Bi0.5Li0.5TiO3 increasing. As x increases, the Curie temperature of the ceramics decreases linearly, while the relative permittivity εr increases. 0.925NaNbO3–0.075(Bi0.5Li0.5)TiO3 ceramic exhibits the relatively large piezoelectric constant (d33 = 58 pC/N), high Curie temperature (TC = 228 °C) and good temperature stability, suggesting that the ceramics are one of new possible candidates for lead-free piezoelectric materials. 相似文献
9.
Polycrystalline ceramics of the perovskite solid solution 0.5Pb(Ni1/3Nb2/3)O3-(0.5-x)-Pb(Zn1/3Nb2/3)O3–xPb(Zr1/2Ti1/2)O3; x=0.0–0.5 (PNN–PZN–PZT) were synthesized by a modified columbite method. Highly dense ceramics lacking parasitic pyrochlore
phases were prepared at a calcination temperature of 950 °C by using a double-crucible configuration, excess PbO (2 mol %),
and a fast heating/cooling rate (20 °C/min). The ceramics were characterized by a variety of techniques including X-ray diffraction,
ferroelectric hysteresis loop measurements, field-induced longitudinal strain measurements, and electron microscopy. It was
observed that the remanent polarization exhibited a significant increase with increasing x. In addition, the squareness of
the hysteresis loop increased quasi-linearly as the molar fraction of PZT increased. The maximum spontaneous polarization
and remanent polarization for the x=0.5 composition were 31.9 μC/cm2 and 25.2 μC/cm2, respectively. Moreover, the data were analyzed to show the evolution of the micro-domain state as a function of the molar
fraction of PZT.
PACS 77.22.-d; 77.80.Bh; 77.84.Dy; 61.10.Nz; 77.80.Dj 相似文献
10.
(100-x)ZrO2(x)Bi2O3 (x = 5, 10, 15) system has been synthesized by solid-state reaction technique. Tetragonal Bi7.38Zr0.62O12.31 phase has formed in all the samples after sintering at 850 °C for 24 h. Apart from this, ZrO2 and Bi2O3 are also identified as minority phases. The volume fraction of Bi7.38Zr0.62O12.31 phase increases with increasing concentration of Bi2O3. The AC conductivity plots exhibit phase transition at 570 °C and 460 °C for x = 10 and x = 15 samples, respectively. The maximum conductivity is observed (1.60 mS/cm) in x = 15 sample. These results are correlated and supported with microstructural and thermal analysis. 相似文献
11.
Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications 总被引:2,自引:0,他引:2
Ki-Bok Kim David K. Hsu Bongyoung Ahn Young-Gil Kim Daniel J. Barnard 《Ultrasonics》2010,50(8):790-797
This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5 MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers. 相似文献
12.
Sunanda Kakroo Arvind Kumar S.K. Mishra Vijay Singh Pramod K. Singh 《Phase Transitions》2016,89(3):211-220
In the present work, lead-free piezoelectric ceramics (Na0.5Bi0.5)TiO3 –xCuO–yNiO (for x = 0.0, 0.02, 0.04 and 0.06) have been prepared by a conventional solid-state reaction method. An investigation of CuO and NiO doping in bismuth sodium titanate (BNT) and a study of the structure, morphology, and dielectric and ferroelectric properties of the NBT–CuNi system have been conducted. Phase and microstructural analysis of the (Na0.5Bi0.5)TiO3 (NBT) based ceramics has been carried out using X-ray diffraction and scanning electron microscopy (SEM) techniques. Field emission scanning electron microscopy (FE-SEM) images showed that inhibition of grain growth takes place with increasing Cu and Ni concentration. The results indicate that the co-doping of NiO and CuO is effective in improving the dielectric and ferroelectric properties of NBT ceramics. Temperature-dependent dielectric studies have also been carried out at room temperature to 400 °C at different frequencies. The NBT ceramics co-doped with x = 0.06 and y = 0.06 exhibited an excellent dielectric constant ?r = 1514. The study suggests that there is enormous scope of application of such materials in the future for actuators, ultrasonic transducers and high-frequency piezoelectric devices. 相似文献
13.
The present paper reports the reactivity between TiO2 and oxygen and the related charge transfer at 298 and 1,073 K. The studies were performed using work function measurements. It was found that oxidation of TiO2 at 1,073 K and p(O2) = 75 kPa, initially standardized at 1,173 K and p(O2) = 10 Pa, results in work function changes that are consistent with the theoretical model of the charge transfer during oxygen chemisorption and oxygen incorporation at the absence of structural transitions. However, oxidation of TiO2 at 298 K, p(O2) = 75 kPa, which has been initially standardized at 1,173 K in extremely reducing conditions at p(O2) = ∼10−10 Pa, results in work function changes that are consistent with low-dimensional structural changes of the surface layer. It is shown that oxidation of strongly reduced TiO2 at 298 K results in a decrease of work function, which cannot be explained without assuming the structural changes of the outermost surface layer. 相似文献
14.
Changrong Zhou Xinyu Liu Weizhou Li Changlai Yuan Guohua Chen 《Current Applied Physics》2010,10(1):93-98
Lead-free piezoelectric ceramics (1 − x − y)Bi0.5Na0.5TiO3−xBi0.5K0.5TiO3− yBiGaO3 have been fabricated by an ordinary sintering technique, and their structure and electrical properties and depolarization temperature have been studied. The results of X-ray diffraction reveal that Bi0.5K0.5TiO3 and BiGaO3 diffuse into the Bi0.5Na0.5TiO3 lattices to form a new solid solution with a pure perovskite structure. An obvious change in microstructure with increasing concentration of Bi0.5K0.5TiO3 and BiGaO3 was observed. The piezoelectric constant d33 and the electromechanical coupling factor kp of the ceramics attain maximum values of 165 pC/N and 0.346 at y = 0.01(x = 0.18) and x = 0.21(y = 0.01), respectively. The temperature dependence of dielectric constant indicates an obvious relaxor characteristic with strong frequency dependence of dielectric constant. The depolarization temperature decreased with increasing content of BiGaO3 and first decreases and then increases with increasing amount of Bi0.5K0.5TiO3. 相似文献
15.
I. O. Troyanchuk M. V. Bushinsky D. V. Karpinsky V. Sirenko V. Sikolenko V. Efimov 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,73(3):375-381
The Bi1−xAxFeO3−
δ (A = Sr, Pb)
systems have been studied using the X-ray, neutron powder
diffraction and magnetization measurements in a magnetic field up to
14 T. It was found that around x ∼ 0.06 the crystal symmetry
changes from a rhombohedral (space group R3c) to
pseudo-tetragonal. In the composition range
0.07 ≤ x ≤ 0.14 the phases with different symmetry of
the unit cell coexist independent of synthesis conditions. The
neutron powder diffraction shows that the iron ions have average
oxidation state close to 3+. The magnetic structure for
Bi0.5Sr0.5FeO3−
δ is found to be G-type
antiferromagnetic with magnetic moment of about
3.8 μB/Fe3+. The weak ferromagnetic state due to
magnetoelectric interactions was revealed in the lightly doped
rhombohedrally distorted compositions. No evidence for a spontaneous
magnetization was observed for the pseudo-tetragonal phases. These
compositions show irreversible nonlinear magnetization vs. field
behavior apparently due to small local deviations from the
collinearity of the magnetic moments. 相似文献
16.
17.
We report the phase diagram of the lead‐free ternary (Bi0.5Na0.5)TiO3–(Bi0.5K0.5)TiO3–(K0.5Na0.5)NbO3 (BNT–BKT–KNN) system and study the switching characteristics of the morphotropic phase boundary (MPB). The addition of KNN intrinsically changes the structural nature of the system with shift of MPB type from (I) to (II), and also adjusts the depolarization temperature (Td) to room temperature. Accordingly, a high electrostrictive response with large electrostrictive coefficient Q33 (~0.022–0.027 m4/C2) and a good thermostability comparable with that of traditional Pb‐based electrostrictors was achieved in MPB (II) compositions. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
18.
M. Morcrette A. Gutiérrez-Llorente A. Laurent J. Perrière P. Barboux J.P. Boilot O. Raymond T. Brousse 《Applied Physics A: Materials Science & Processing》1998,67(4):425-428
x La2/3+yTiO3-δ perovskite (with δ≤0.5) were deposited by the laser ablation technique from Li0.33La0.56TiO3 targets. Their growth onto MgO substrateswas studied as a function of the oxygen pressure. For films grown in vacuum (10-6 mbar), a La0.63TiO2.5 composition was obtained, meaning that Ti3+ alone is present in the films, while Li ions are not incorporated under these conditions. This material shows good electric
conductivity (ρ=500 mΩ cm). By contrast, insulating films with a Li0.1La0.70TiO3 composition corresponding to the Ti4+ species were obtained at high oxygen pressures (>0.05 mbar). For all conditions, textured films were grown with different
orientations depending on the temperature and the oxygen pressure.
Received: 10 September 1997/Accepted: 24 November 1997 相似文献
19.
High-quality, large-size lead-free (1 – x)Na0.5Bi0.5TiO3–xBaTiO3 ((1 – x)NBT–xBT) single crystals (x = 0, 0.025, 0.0325 and 0.05) were grown using the Czochralski method. Dielectric and transmitted light intensity properties were measured for these crystals. The broad anomalies exhibited in the temperature dependence of the transmitted light corresponded to structural and dielectric anomalies and were related to the temperature dependence of polar regions and the appearance of a long-range ferroelectric state. We explain our results based on local electromechanical fields, by inhomogeneity of the ion distribution and the mismatch in ion size. We suggested that the NBT–BT system can be a promising lead-free piezoelectric material for ultrasonic delay-line applications, broadband transducers and sensors. 相似文献
20.
H. J. Hilke 《Applied Physics A: Materials Science & Processing》1973,1(6):317-329
Summary The theory of piezoelectric transducer vibrations, which may be treated as onedimensional, is developed in detail for thin
discs vibrating in a pure thickness extensional mode. An effort has been made to obtain relations of general validity, which
include losses, and which are in a simple explicit form convenient for practical calculations. The behaviour of transducers
is discussed with special attention to their characteristics at the two fundamental frequencies, the so-called parallel and
series resonances. Several peculiarities occur when transducers are coupled to media with considerably different acoustic
impedances. These peculiarities are discussed and illustrated by numerical results for quartz and PZT 4 piezoelectric discs
radiating into water, air and liquid hydrogen. The application of the theory to different types of vibrations is briefly illustrated
for thin bars vibrating longitudinally. Short discussions are included on compound transducer systems, and on the properties
of thin discs as receivers. 相似文献