High-power Piezoelectric Applications Research Articles

High-Power Piezoelectric Characteristics of C-Axis Crystal-Oriented (Sr,Ca)2NaNb5O15 Ceramics

The high-power piezoelectric characteristics of c-axis crystal-oriented (Sr,Ca)2NaNb5O15 (SCNN) ceramics were studied by the constant-motional-current driving method, and compared with those of the randomly oriented ceramics superior to those of hard Pb(Ti,Zr)O3 (PZT) ceramics. The c-axis crystal-oriented SCNN ceramic showed a large Lotgering factor of 0.98. The effective piezoelectric constant d33* was 260 pm/V, as large as those of hard PZT ceramics. In the 31-mode of the rectangular plate, the quality factor, Q, was five times larger than that of the randomly oriented ceramic, and almost constant at approximately 3300 up to the maximum vibration velocity of 1.84 m/s rms. The resonant frequency change was also stable up to a vibration velocity of 1.84 m/s rms. The change was approximately +0.05% in the driving range, which was much smaller than that of +0.8% of the randomly oriented ceramic. The high-power piezoelectric characteristics were also clarified by a comparison with the mechanical characteristics. Therefore, the highly c-axis crystal-oriented SCNN ceramics are good candidates for high-power piezoelectric applications in comparison with hard PZT ceramics.

ハイパワー圧電応用を目指したPb(Mn1/3Nb2/3)O3-PbTiO3-PbZrO3系圧電材料の探索

ハイパワー圧電応用を目指したPb(Mn1/3Nb2/3)O3-PbTiO3-PbZrO3系圧電材料の探索

Structural, dielectric relaxation and piezoelectric characterization of Sr 2+ substituted modified PMS-PZT ceramic

Pyrochlore phase free [Pb 0.94Sr 0.06] [(Mn 1/3Sb 2/3) 0.05(Zr 0.53Ti 0.47) 0.95] O 3 ceramics has been synthesized with pure Perovskite phase by semi-wet route using the columbite precursor method. The field dependences of the dielectric response and the conductivity have been measured in a frequency range from 50 Hz to 1 MHz and in a temperature range from 303 K to 773 K. An analysis of the real and imaginary parts of the dielectric permittivity with frequency has been performed, assuming a distribution of relaxation times. The scaling behavior of the dielectric loss spectra suggests that the distribution of the relaxation times is temperature independent. The SEM photographs of the sintered specimens present the homogenous structures and well-grown grains with a sharp grain boundary. The material exhibits tetragonal structure. When measured at frequency (100 Hz), the polarization shows a strong field dependence. Different piezoelectric figures of merit ( k p, d 33 and Q m) of the material have also been measured obtaining their values as 0.53, 271 pC/N and 1115, respectively, which are even higher than those of pure PZT with morphotropic phase boundary (MPB) composition. Thus the present ceramics have the optimal overall performance and are promising candidates for the various high power piezoelectric applications.

Large Amplitude Piezoelectric Properties of KNbO3-based Lead-free Ferroelectric Ceramics

High power piezoelectric characteristics of Mn doped KNbO3 (KN+MnCO3 x wt% x=0∼0.8 wt%, KN-Mnx) ceramics were firstly reported in this paper. Mechanical quality factor, Qm, of KN-Mn x ceramics at small amplitude vibration increased with increasing Mn content and the Qm of KN-Mn0.8 ceramic reached about 820. The maximum vibration velocity, vo-p, about 2.3 m/s was obtained for KN-Mn0.8 with Qm=820. The Qm at large-amplitude vibration for KN-Mn0.8 and Pb(Zr,Ti)O3 [PZT]-based ceramics [N6] decreased with increasing the vo-p. The Qm of KN-Mn0.8 was smaller than that of N6 at the small-amplitude vibration. However, at the large amplitude vibration, vo-p>0.6 m/s, the Qm value of KN-Mn0.8 was larger than that of N6. Therefore, it was clarified that KN-based lead-free piezoelectric ceramics possess superior mechanical stability at large-amplitude vibration. This is very good sign for high power piezoelectric applications.

High Power Piezoelectric Characteristics for Perovskite-Type Lead-Free Ferroelectric Ceramics

High power piezoelectric characteristics of perovskite-type lead-free ferroelectric ceramics, 0.88(Bi0.5Na0.5) TiO3-0.04(Bi0.5Li0.5)TiO3-0.08(Bi0.5Na0.5)TiO3 + MnCO3 0.4 wt% [BNLKT4-8Mn0.4] and KNbO3 + MnCO3 0.8 wt% [KN-Mn0.8], were focused on under large-amplitude vibration as compared with those of Pb(Zr,Ti)O3 [PZT]-based ceramics. The maximum vibration velocities, v o-p for BNLKT4-8Mn0.4 and KN-Mn0.8 reached larger than 2 m/s. A mechanical quality factor, Qm, at large-amplitude vibration for all compositions including PZT-based ceramics decreased with increasing the v o-p. The Qms of BNLKT and KN ceramics were smaller than that of hard PZT [N6] at the small-amplitude vibration. However, at the large amplitude vibration level of v o-p > 0.6 m/s, Qm values of BNLKT and KN are larger than that of N6. Therefore, lead–free piezoelectric ceramics such as BNLKT-Mn0.4 and KN-Mn08 possess superior mechanical stability at large-amplitude vibration. This is very good sign for high power piezoelectric applications.

High-Power Characteristics of Thickness Shear Mode for Textured SrBi2Nb2O9 Ceramics

The high-power piezoelectric characteristics of the thickness shear mode for <00l> oriented ceramics of bismuth layer structured ferroelectrics (BLSF), SrBi2Nb2O9 (SBN), were studied by the constant current driving method. These textured ceramics were fabricated by the templated grain growth (TGG) method, and the Lotgering factor was 95%. The vibration of the thickness shear mode in the textured SBN ceramics was stable at the vibration velocity of 2.0 m/s. The resonant frequency was almost constant with increasing vibration velocity in the textured SBN ceramics, however, it decreased with increasing vibration velocity in the randomly oriented SBN ceramics. In the case of Pb(Mn,Nb)O3–Pb(Zr,Ti)O3 ceramics, the vibration velocity of the thickness shear mode was saturated at more than 0.3 m/s, and the resonant frequency decreased at lower vibration velocity than in the case of SBN ceramics. The dissipation power density of the textured SBN ceramics was the lowest among those of the randomly oriented SBN and Pb(Mn,Nb)O3–PZT ceramics. The thickness shear mode of textured SBN ceramics is a good candidate for high-power piezoelectric applications.

High-power piezoelectric characteristics of textured bismuth layer structured ferroelectric ceramics

Abstract-The high-power piezoelectric characteristics in h001i oriented ceramics of bismuth layer structured ferroelectrics (BLSF), SrBi(2)Nb(2)O(9) (SBN), (Bi,La)(4)Ti(3)O(12) (BLT), and CaBi(4)Ti(4)O(15) (CBT), were studied by a constant voltage driving method. These textured ceramics were fabricated by a templated grain growth (TGG) method, and their Lotgering factors were 95%, 97%, and 99%, respectively. The vibration velocities of the longitudinal mode (33-mode) increased proportionally to an applied electric field up to 2.5 m/s in these textured BLSF ceramics, although, the vibration velocity of the 33-mode was saturated at more than 1.0 m/s in the Pb(Mn,Nb)O(3)-PZT ceramics. The resonant frequencies were constant up to the vibration velocity of 2.5 m/s in the SBN and CBT textured ceramics; however, the resonant frequency decreased with increasing over the vibration velocity of 1.5 m/s in the BLT textured ceramics. The dissipation power density of the BLT was almost the same as that of the Pb(Mn,Nb)O(3)-PZT ceramics. However, the dissipation power densities of the SBN and CBT were lower than those of the BLT and Pb(Mn,Nb)O(3)-PZT ceramics. The textured SBN and CBT ceramics are good candidates for high-power piezoelectric applications.

Texture Fraction Dependences of High-Power Characteristics for Textured SrBi2Nb2O9 Ceramics

Texture fraction dependences of high-power characteristics for textured SrBi2Nb2O9 (SBN) ceramics were studied. The resonant frequency change with increasing vibration velocity decreased with increasing texture fraction. Furthermore, the linearity of vibration velocity increased with increasing texture fraction. In the case of 95%-textured SBN specimen, the resonant frequency was almost constant and the vibration velocity changed linearly with the applied electric field up to a vibration velocity of 2.6 m/s. Highly textured SBN ceramics are good candidates for high-power piezoelectric applications.

The influence of Yb and Nd substituents on high-power piezoelectric properties of PMS–PZT ceramics

This paper presents an investigation on the effect of Yb and Nd substituents on the piezoelectric properties and vibration velocity of 0.05Pb(Mn 1/3Sb 2/3)O 3–0.95Pb(Zr 0.52Ti 0.48)O 3 piezoelectric ceramics. The X-ray diffraction (XRD) measurements were performed on the doped samples and the results indicate that all the Yb-doped samples exhibit a single phase of perovskite structures in tetragonal symmetry and pyrochlore phases are found in specimens with high Nd dopant. The “soft” characteristic is improved by adding small amount of Yb 2O 3 and the optimum properties of Yb-doped PMSZ5 ceramics are achieved at x = 2 mol% ( d 33 = 390 pC/N, ɛ r = 1380, K p = 0.61, tan δ = 0.41%, Q m = 800). Meanwhile, the piezoelectric properties of all Nd 2O 3-doped specimens are found deteriorating. Vibration velocity at Δ T = 20 °C, one of the most important factors for high-power piezoelectric application, is found as high as 1100 mm/s for 2 mol% Yb-doped specimens, which is about 2.7 times higher than that of the conventional hard PZT ceramics.

High-Power Piezoelectric Vibration Characteristics of Textured SrBi2Nb2O9 Ceramics

The high-power piezoelectric vibration characteristics of textured SrBi2Nb2O9 (SBN) ceramics, that is bismuth-layer-structured ferroelectrics, were studied in the longitudinal mode (33-mode) by constant current driving method and compared with those of ordinary randomly oriented SBN and widely used Pb(Ti,Zr)O3 (PZT) ceramics. In the case of textured SBN ceramics, resonant properties are stable up to a vibration velocity of 2.6 m/s. Vibration velocity at resonant frequency increases proportionally with the applied electric field, and resonant frequency is almost constant in high-vibration-velocity driving. On the other hand, in the case of randomly oriented SBN and PZT ceramics, the increase in vibration velocity is not proportional to the applied high electric field, and resonant frequency decreases with increasing vibration velocity. The resonant sharpness Q of textured SBN ceramics is about 2000, even at a vibration velocity of 2.6 m/s. Therefore, textured SBN ceramics are good candidates for high-power piezoelectric applications.

Low Temperature Coefficient of Resonance Frequency Composition in the System Pb(Zr,Ti)O3—Pb(Mn1/3 Nb2/3)O3

Pb(Zr,Ti)O3–Pb(Mn1/3 Nb2/3)O3 (PZT–PMnN) system has been studied for high‐power piezoelectric applications. This study investigates this system to find out the composition with high‐power density piezoelectric characteristics and low tem‐perature coefficient of resonance frequency (TCF). It was found that the composition 0.9PZT–0.1PMnN (Zr/Ti = 0.51/0.49) modified with 6 mol% Sr exhibits a TCF of −8 ppm/°C (−20 to +80°C). Further, the dielectric and piezoelectric properties of this composition are as follows: kp= 0.53; Qm= 800; d33= 274; ε33/ε0= 1290 and tan δ=1.1%, which shows the suitability of this composition for ultrasonic devices used under fluctuating thermal environment.

Effect of Yb Addition on the Sintering Behavior and High Power Piezoelectric Properties of Pb(Zr,Ti)O3–Pb(Mn,Nb)O3

0.9Pb(Zr0.61Ti0.39)–0.1Pb(Mn1/3Nb2/3)O3 piezoelectric ceramics doped with Yb2O3 were prepared by conventional ceramic processing, and the effects of the Yb doping on the sintering behavior and high power piezoelectric properties were investigated. X-ray diffractomer (XRD) measurements indicated that the piezoelectric ceramics with Yb2O3 in this study were a single phase of polycrystalline perovskite. The sintering density was strongly affected by small amount of Yb2O3 addition. Vibration velocity, which is one of the most important factors for high power piezoelectric applications, as high as 1.0 m/s (rms value), was obtained from the 0.2 mol% Yb2O3 doped sample. This value is about 2.5 times higher than that for commercialized hard Pb(Zr,Ti)O3 ceramics.