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Bismuth-modified BiScO3–PbTiO3 piezoelectric ceramics with high Curie temperature
Materials Letters 62 (2008) 3567–3569
Contents lists available at ScienceDirect
Materials Letters j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / m a t l e t
Bismuth-modified BiScO3–PbTiO3 piezoelectric ceramics with high Curie temperature Yi Chen a,⁎, Jianguo Zhu b, Dingquan Xiao b, Baoquan Qin b, Yihang Jiang b a b
School of Materials Science and Engineering, Southwest University, Chongqing 400715, PR China College of Materials Science and Engineering, Sichuan University, Chengdu 610064, PR China
A R T I C L E
I N F O
Article history: Received 13 November 2007 Accepted 27 March 2008 Available online 4 April 2008 Keywords: High-temperature piezoelectric ceramics Piezoelectric properties Perovskite Curie temperature
A B S T R A C T New piezoelectric ceramics, 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 (x = 0.04~0.10), were prepared by using conventional solid phase processing. The results of X-ray diffraction (XRD) show that the ceramics have a single phase tetragonal perovskite structure. The ceramics, poled by normal poling process, have piezoelectric coefficient d33, planar electromechanical coupling factor kp and thickness electromechanical coupling factor kt of 50~60 pC/N, ~11% and ~ 30%, respectively. An extremely high mechanical quality factor Qm of 1540 was obtained at the composition x = 0.08. The Curie temperature (TC) is in the range of 520–550 °C, higher than 490 °C of pure PbTiO3. The combination of good piezoelectric properties and high TC makes these ceramics suitable for elevated temperature piezoelectric devices. © 2008 Elsevier B.V. All rights reserved.
1. Introduction Piezoelectric ceramics based on Pb(ZrxTi1 − x)O3 (PZT) are widely used in electronic and microelectronic devices. Most commercially available PZT formulations have Curie temperature of 300 °C which limits the operating temperatures to ~ 150 °C. However, a number of piezoelectric applications require operating at higher temperatures than are currently available with conventional PZT ceramics [1]. Eitel et al. [2] used a relationship between perovskite tolerance factor and TC to predict that Bi(Me)O3–PbTiO3 systems (Me: Sc, In, Y, Yb, etc.) should have higher TC than PZT. Specifically, BiScO3–PbTiO3 (BSPT) [3] exhibits a morphotropic phase boundary (MPB) at 64 mol% PbTiO3, separating the rhombohedral and tetragonal phases. The TC at the MPB is ~ 450 °C, higher than that of PZT. The combination of high TC with a piezoelectric coefficient d33~450 pC/N, which is comparable to commercial PZT ceramics, make them promising candidates for high temperature sensing applications. In the BSPT system, the composition 0.15BiScO3–0.85PbTiO3 has the highest TC (~ 525 °C) [4,5]. However, the piezoelectric properties of 0.15BiScO3–0.85PbTiO3 ceramics have not been reported. Perhaps it is because it cannot be poled to be piezoelectrics due to its dc current leakage and large degree of tetragonal distortion [5,6]. Normally, the substitution of alkaline- and rare-earth metals for Pb2+ will reduce the lattice anisotropy and the PbTiO3-based ceramics become much denser [7]. Based on the research of bismuth-modified PbTiO3 [8], the c/a ratio decreases from 1.064 to 1.060 as the bismuth content ⁎ Corresponding author. Fax: +86 23 68254373. E-mail address: [email protected] (Y. Chen). 0167-577X/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2008.03.056
increases from 0 to 8 at.%. Therefore, the substitution of Bi3+ ions for Pb2+ will reduce the c/a ratio of PbTiO3. In previous works [9–11], MnO2 is also generally used to enhance the densification of PbTiO3based ceramics. The objective of the current work is to make it possible to be poled to be piezoelectrics for the composition 0.15BiScO3–0.85PbTiO3. Manganese substituting and bismuth modification were employed to realize it. Therefore, the composition 0.15BiScO3–0.85(Pb1 − 3x / 2Bix) (Ti0.98Mn0.02)O3 were designed. The ceramics were synthesized by conventional ceramic sintering technique, and their structural, dielectric and piezoelectric properties were reported. 2. Experimental procedure 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 (x = 0.04~0.10) ceramics were prepared by conventional ceramic fabrication technique. The raw materials used in the study were Bi2O3(99%), Sc2O3(99%), PbO (99%), TiO2(99.5%) and MnCO3(95%) powder. The powder were mixed by ball milling and calcined at 800 °C–850 °C for 4 h. After thoroughly mixing with 3~5 wt.% of poly (vinyl alcohol) binder, the calcined powders were pressed into discs and sintered in sealed crucibles at 1150 °C for 2 h. Silver paste was coated to form electrodes on both sides of sintered ceramic specimens and subsequently annealed at 700 °C. The specimens were poled in a stirred silicone oil bath at temperature 120 °C, by applying a dc electric field of 70 kV/cm for 10 to 20 min. The crystalline phase of the sintered pellets was identified by X-ray diffraction (XRD) technique using Cu Kα radiation (DX-1000 diffractometer). Surface microstructure was examined by scanning electron
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Y. Chen et al. / Materials Letters 62 (2008) 3567–3569
Fig. 1. XRD patterns of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics.
Fig. 2. Surface microstructure of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics for x = 0.10.
microscopy (SEM) (Hitachi S-450). Dielectric properties as a function of temperature were measured from 0.1 kHz to 1 MHz frequencies using a computer controlled precision LCR meter (HP4284A) with a specially designed multi-sample furnace. The piezoelectric constant d33 was measured using a Berlincourt-type quasi-static d33 meter (ZJ-3A, Institute of Acoustic Academia Sinica). The electromechanical coupling coefficients were determined by a resonance and antiresonance method performed on the basis of IEEE standards using an impedance analyzer (Agilent, HP4294A).
and 300, and seems to be relatively independent of the composition. Compared to other high temperature piezoelectric materials, as shown in Table 2 and summarized by Zhang et al. [14], the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics have a relatively high TC (N 500 °C) and large mechanical quality factor Qm. The highest Qm
3. Results and discussion Fig. 1 shows X-ray diffraction patterns of the synthesized 0.15BiScO3–0.85(Pb1 − 3x / 2 Bix)(Ti0.98Mn0.02)O3 ceramics. The patterns indicate that the ceramics possess a pure phase of perovskite structure, and the crystalline symmetry is the tetragonal. From the XRD data, the lattice constants were calculated and revealed in Table 1, in which the c/a ratio of PbTiO3 and BSPT85 were also listed for comparison. A gradual decrease from 1.049 (x = 0.04) to 1.046 (x = 0.10) is observed in the c/a ratio, which implying that the substitution of bismuth for lead reduces the degree of tetragonal distortion. Surface morphology was shown in Fig. 2 for x = 0.10. It can be found that the ceramics were well densified. The temperature dependence of dielectric constant and loss at 10 kHz is shown in Fig. 3 for the four samples. As shown in Fig. 3(a), the peak temperature (corresponding to the Curie temperature TC) shifts toward the lower temperature side with increasing bismuth content. Nevertheless the lowest TC in these samples maintains above 520 °C, higher than that of pure PbTiO3 (~ 490 °C). The dielectric loss tanδ rises sharply with increasing temperature in the compositions investigated, as exhibited in Fig. 3(b), even though all their room temperature tanδ are smaller than 0.02. This implies that the conductivity increases with increasing temperature in the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix) (Ti0.98Mn0.02)O3 system, and the sharp rise phenomenon becomes more pronounced with increasing bismuth content. For actual applications, more attentions should be paid to decrease the high temperature conductivity. Though possessing large anisotropy in crystalline structure, the 0.15BiScO3–0.85 (Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics can be poled to be piezoelectrics by normal poling process. The piezoelectric coefficient d33 and planar electromechanical coupling factor kp are 50~60 pC/N and 0.10–0.13 respectively. A complete summary of the measured properties of the ceramics and the comparison with some high temperature piezoelectric materials are given in Table 2. Compared to the kp, the thickness electromechanical coupling factors (kt) of the samples clearly are lager values, which is analogous to many modified PT piezoelectric ceramics [7,13]. The substitution of bismuth for lead led to an increase in the relative permittivity and a slight decrease in the dielectric loss. However, the value of relative permittivity ε keeps in between 200
Table 1 Lattice constants of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics Composition
a, nm
c, nm
c/a
Reference
PbTiO3 BSPT85 x = 0.04 x = 0.06 x = 0.08 x = 0.10
– – 0.3921 0.3924 0.3935 0.3928
– – 0.4114 0.4113 0.4117 0.4107
1.064 1.050 1.049 1.048 1.046 1.046
[12] [3] – – – –
Fig. 3. Temperature dependence of dielectric constant (a) and loss (b) at 10 kHz for 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics.
Y. Chen et al. / Materials Letters 62 (2008) 3567–3569 Table 2 Piezoelectric properties of the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics are in contrasted with a number of high temperature piezoelectric materials Composition d33, pC/N kp Modified PT BSPT66–Mn BSPT64 x = 0.04 x = 0.06 x = 0.08 x = 0.10
56 270 460 52 50 51 60
– 0.48 0.56 0.10 0.11 0.12 0.13
kt
Qm
ε (1 kHz) Tanδ TC, °C Reference (1 kHz), %
– 0.50 – 0.35 0.31 0.28 0.34
1300 200 – 709 738 1541 553
190 – – 225 228 241 262
– – – 1.4 1.2 0.9 0.9
470 468 450 552 543 531 522
[15,16] [17] [3] – – –
1540 is obtained at the composition x = 0.08, which shows potential for use in high power applications.
4. Conclusions New high Curie temperature piezoelectric ceramics 0.15BiScO3– 0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 were synthesized by conventional ceramic sintering technique in this study. The crystalline structural, dielectric and piezoelectric properties of the ceramics were studied. The results of X-ray diffraction (XRD) data show that the ceramics possess a single phase perovskite structure with tetragonal symmetry. The ceramics can be poled using normal poling process, and exhibits good piezoelectric properties with piezoelectric coefficient d33 and planar electromechanical coupling factor kp of 50~60 pC/N and 0.10–0.13, respectively. The TC shifted to lower temperature with the substitution of bismuth for lead. A value of mechanical quality factor Qm, as high as 1540, was obtained for x = 0.08. The piezoelectric properties together with a TC exceeding 520 °C, make the 0.15BiScO3– 0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics promising candidates for elevated temperatures piezoelectric applications, especially in high power devices.
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Acknowledgment We are pleased to acknowledge the support from the Natural Science Foundation of China (NSFC) under Grant No. 60471044 and Specialized Research Fund for the Doctoral Program of High Education of China (SRFDP) under Grant No. 20020610014. References [1] R.C. Turner, P.A. Fuierer, R.E. Newnham, T.R. Shrout, Appl. Acoust. 41 (1994) 299–324. [2] R.E. Eitel, C.A. Randall, T.R. Shrout, P.W. Rehrig, W. Hackenberger, S.E. Park, Jpn. J. Appl. Phys. Part 1 40 (2001) 5999–6002. [3] R.E. Eitel, C.A. Randall, T.R. Shrout, S.E. Park, Jpn. J. Appl. Phys. Part 1 41 (2002) 2099–2104. [4] R.E. Eitel, S.J. Zhang, T.R. Shrout, C.A. Randall, I. Levin, J. Appl. Phys. 96 (2004) 2828–2831. [5] Y. Shimojo, R. Wang, T. Sekiya, T. Nakamura, L.E. Cross, Ferroelectrics 284 (2003) 121–128. [6] Y. Inaguma, A. Miyaguchi, M. Yoshida, T. Katsumata, Y. Shimojo, R. Wang, et al., J. Appl. Phys. 95 (2004) 231–235. [7] T.Y. Chen, S.Y. Chu, S.J. Wu, Y.D. Juang, Sens. Actuators, A, Phys. 101 (2002) 352–357. [8] L. Amarande, C. Miclea, C. Tanasoiu, J. Eur. Ceram. Soc. 22 (2002) 1269–1275. [9] P. Duran, J.F. Fernandez, C. Moure, J. Mater. Sci. Lett. 10 (1991) 917–919. [10] C.M. Beck, N.W. Thomas, I. Thompson, J. Eur. Ceram. Soc. 18 (1998) 1685–1693. [11] T. Zhou, W. Peng, X. Shang, K. Zheng, A. Kuang, Ferroelectrics 263 (2001) 297–302. [12] B. Jaffe, W.R. Cook, H. Jaffe, Piezoelectric Ceramics, Academic Press, Marietta, Ohio, 1971. [13] T.Y. Chen, S.Y. Chu, Y.D. Juang, Sens. Actuators, A, Phys. 102 (2002) 6–10. [14] S. Zhang, R. Xia, L. Lebrun, D. Anderson, T.R. Shrout, Mater. Lett. 59 (2005) 3471–3475. [15] S. Ikegami, I. Ueda, T. Nagata, J. Acoust. Soc. Am. 50 (1971) 1060–1066. [16] D. Damjanovic, T.R. Gururaja, L.E. Cross, Am. Ceram. Soc. Bull. 66 (1987) 699–703. [17] S. Zhang, R.E. Eitel, C.A. Randall, T.R. Shrout, E.F. Alberta, Appl. Phys. Lett. 86 (2005) 262904.
Contents lists available at ScienceDirect
Materials Letters j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / m a t l e t
Bismuth-modified BiScO3–PbTiO3 piezoelectric ceramics with high Curie temperature Yi Chen a,⁎, Jianguo Zhu b, Dingquan Xiao b, Baoquan Qin b, Yihang Jiang b a b
School of Materials Science and Engineering, Southwest University, Chongqing 400715, PR China College of Materials Science and Engineering, Sichuan University, Chengdu 610064, PR China
A R T I C L E
I N F O
Article history: Received 13 November 2007 Accepted 27 March 2008 Available online 4 April 2008 Keywords: High-temperature piezoelectric ceramics Piezoelectric properties Perovskite Curie temperature
A B S T R A C T New piezoelectric ceramics, 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 (x = 0.04~0.10), were prepared by using conventional solid phase processing. The results of X-ray diffraction (XRD) show that the ceramics have a single phase tetragonal perovskite structure. The ceramics, poled by normal poling process, have piezoelectric coefficient d33, planar electromechanical coupling factor kp and thickness electromechanical coupling factor kt of 50~60 pC/N, ~11% and ~ 30%, respectively. An extremely high mechanical quality factor Qm of 1540 was obtained at the composition x = 0.08. The Curie temperature (TC) is in the range of 520–550 °C, higher than 490 °C of pure PbTiO3. The combination of good piezoelectric properties and high TC makes these ceramics suitable for elevated temperature piezoelectric devices. © 2008 Elsevier B.V. All rights reserved.
1. Introduction Piezoelectric ceramics based on Pb(ZrxTi1 − x)O3 (PZT) are widely used in electronic and microelectronic devices. Most commercially available PZT formulations have Curie temperature of 300 °C which limits the operating temperatures to ~ 150 °C. However, a number of piezoelectric applications require operating at higher temperatures than are currently available with conventional PZT ceramics [1]. Eitel et al. [2] used a relationship between perovskite tolerance factor and TC to predict that Bi(Me)O3–PbTiO3 systems (Me: Sc, In, Y, Yb, etc.) should have higher TC than PZT. Specifically, BiScO3–PbTiO3 (BSPT) [3] exhibits a morphotropic phase boundary (MPB) at 64 mol% PbTiO3, separating the rhombohedral and tetragonal phases. The TC at the MPB is ~ 450 °C, higher than that of PZT. The combination of high TC with a piezoelectric coefficient d33~450 pC/N, which is comparable to commercial PZT ceramics, make them promising candidates for high temperature sensing applications. In the BSPT system, the composition 0.15BiScO3–0.85PbTiO3 has the highest TC (~ 525 °C) [4,5]. However, the piezoelectric properties of 0.15BiScO3–0.85PbTiO3 ceramics have not been reported. Perhaps it is because it cannot be poled to be piezoelectrics due to its dc current leakage and large degree of tetragonal distortion [5,6]. Normally, the substitution of alkaline- and rare-earth metals for Pb2+ will reduce the lattice anisotropy and the PbTiO3-based ceramics become much denser [7]. Based on the research of bismuth-modified PbTiO3 [8], the c/a ratio decreases from 1.064 to 1.060 as the bismuth content ⁎ Corresponding author. Fax: +86 23 68254373. E-mail address: [email protected] (Y. Chen). 0167-577X/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2008.03.056
increases from 0 to 8 at.%. Therefore, the substitution of Bi3+ ions for Pb2+ will reduce the c/a ratio of PbTiO3. In previous works [9–11], MnO2 is also generally used to enhance the densification of PbTiO3based ceramics. The objective of the current work is to make it possible to be poled to be piezoelectrics for the composition 0.15BiScO3–0.85PbTiO3. Manganese substituting and bismuth modification were employed to realize it. Therefore, the composition 0.15BiScO3–0.85(Pb1 − 3x / 2Bix) (Ti0.98Mn0.02)O3 were designed. The ceramics were synthesized by conventional ceramic sintering technique, and their structural, dielectric and piezoelectric properties were reported. 2. Experimental procedure 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 (x = 0.04~0.10) ceramics were prepared by conventional ceramic fabrication technique. The raw materials used in the study were Bi2O3(99%), Sc2O3(99%), PbO (99%), TiO2(99.5%) and MnCO3(95%) powder. The powder were mixed by ball milling and calcined at 800 °C–850 °C for 4 h. After thoroughly mixing with 3~5 wt.% of poly (vinyl alcohol) binder, the calcined powders were pressed into discs and sintered in sealed crucibles at 1150 °C for 2 h. Silver paste was coated to form electrodes on both sides of sintered ceramic specimens and subsequently annealed at 700 °C. The specimens were poled in a stirred silicone oil bath at temperature 120 °C, by applying a dc electric field of 70 kV/cm for 10 to 20 min. The crystalline phase of the sintered pellets was identified by X-ray diffraction (XRD) technique using Cu Kα radiation (DX-1000 diffractometer). Surface microstructure was examined by scanning electron
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Y. Chen et al. / Materials Letters 62 (2008) 3567–3569
Fig. 1. XRD patterns of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics.
Fig. 2. Surface microstructure of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics for x = 0.10.
microscopy (SEM) (Hitachi S-450). Dielectric properties as a function of temperature were measured from 0.1 kHz to 1 MHz frequencies using a computer controlled precision LCR meter (HP4284A) with a specially designed multi-sample furnace. The piezoelectric constant d33 was measured using a Berlincourt-type quasi-static d33 meter (ZJ-3A, Institute of Acoustic Academia Sinica). The electromechanical coupling coefficients were determined by a resonance and antiresonance method performed on the basis of IEEE standards using an impedance analyzer (Agilent, HP4294A).
and 300, and seems to be relatively independent of the composition. Compared to other high temperature piezoelectric materials, as shown in Table 2 and summarized by Zhang et al. [14], the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics have a relatively high TC (N 500 °C) and large mechanical quality factor Qm. The highest Qm
3. Results and discussion Fig. 1 shows X-ray diffraction patterns of the synthesized 0.15BiScO3–0.85(Pb1 − 3x / 2 Bix)(Ti0.98Mn0.02)O3 ceramics. The patterns indicate that the ceramics possess a pure phase of perovskite structure, and the crystalline symmetry is the tetragonal. From the XRD data, the lattice constants were calculated and revealed in Table 1, in which the c/a ratio of PbTiO3 and BSPT85 were also listed for comparison. A gradual decrease from 1.049 (x = 0.04) to 1.046 (x = 0.10) is observed in the c/a ratio, which implying that the substitution of bismuth for lead reduces the degree of tetragonal distortion. Surface morphology was shown in Fig. 2 for x = 0.10. It can be found that the ceramics were well densified. The temperature dependence of dielectric constant and loss at 10 kHz is shown in Fig. 3 for the four samples. As shown in Fig. 3(a), the peak temperature (corresponding to the Curie temperature TC) shifts toward the lower temperature side with increasing bismuth content. Nevertheless the lowest TC in these samples maintains above 520 °C, higher than that of pure PbTiO3 (~ 490 °C). The dielectric loss tanδ rises sharply with increasing temperature in the compositions investigated, as exhibited in Fig. 3(b), even though all their room temperature tanδ are smaller than 0.02. This implies that the conductivity increases with increasing temperature in the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix) (Ti0.98Mn0.02)O3 system, and the sharp rise phenomenon becomes more pronounced with increasing bismuth content. For actual applications, more attentions should be paid to decrease the high temperature conductivity. Though possessing large anisotropy in crystalline structure, the 0.15BiScO3–0.85 (Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics can be poled to be piezoelectrics by normal poling process. The piezoelectric coefficient d33 and planar electromechanical coupling factor kp are 50~60 pC/N and 0.10–0.13 respectively. A complete summary of the measured properties of the ceramics and the comparison with some high temperature piezoelectric materials are given in Table 2. Compared to the kp, the thickness electromechanical coupling factors (kt) of the samples clearly are lager values, which is analogous to many modified PT piezoelectric ceramics [7,13]. The substitution of bismuth for lead led to an increase in the relative permittivity and a slight decrease in the dielectric loss. However, the value of relative permittivity ε keeps in between 200
Table 1 Lattice constants of 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics Composition
a, nm
c, nm
c/a
Reference
PbTiO3 BSPT85 x = 0.04 x = 0.06 x = 0.08 x = 0.10
– – 0.3921 0.3924 0.3935 0.3928
– – 0.4114 0.4113 0.4117 0.4107
1.064 1.050 1.049 1.048 1.046 1.046
[12] [3] – – – –
Fig. 3. Temperature dependence of dielectric constant (a) and loss (b) at 10 kHz for 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics.
Y. Chen et al. / Materials Letters 62 (2008) 3567–3569 Table 2 Piezoelectric properties of the 0.15BiScO3–0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics are in contrasted with a number of high temperature piezoelectric materials Composition d33, pC/N kp Modified PT BSPT66–Mn BSPT64 x = 0.04 x = 0.06 x = 0.08 x = 0.10
56 270 460 52 50 51 60
– 0.48 0.56 0.10 0.11 0.12 0.13
kt
Qm
ε (1 kHz) Tanδ TC, °C Reference (1 kHz), %
– 0.50 – 0.35 0.31 0.28 0.34
1300 200 – 709 738 1541 553
190 – – 225 228 241 262
– – – 1.4 1.2 0.9 0.9
470 468 450 552 543 531 522
[15,16] [17] [3] – – –
1540 is obtained at the composition x = 0.08, which shows potential for use in high power applications.
4. Conclusions New high Curie temperature piezoelectric ceramics 0.15BiScO3– 0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 were synthesized by conventional ceramic sintering technique in this study. The crystalline structural, dielectric and piezoelectric properties of the ceramics were studied. The results of X-ray diffraction (XRD) data show that the ceramics possess a single phase perovskite structure with tetragonal symmetry. The ceramics can be poled using normal poling process, and exhibits good piezoelectric properties with piezoelectric coefficient d33 and planar electromechanical coupling factor kp of 50~60 pC/N and 0.10–0.13, respectively. The TC shifted to lower temperature with the substitution of bismuth for lead. A value of mechanical quality factor Qm, as high as 1540, was obtained for x = 0.08. The piezoelectric properties together with a TC exceeding 520 °C, make the 0.15BiScO3– 0.85(Pb1 − 3x / 2Bix)(Ti0.98Mn0.02)O3 ceramics promising candidates for elevated temperatures piezoelectric applications, especially in high power devices.
3569
Acknowledgment We are pleased to acknowledge the support from the Natural Science Foundation of China (NSFC) under Grant No. 60471044 and Specialized Research Fund for the Doctoral Program of High Education of China (SRFDP) under Grant No. 20020610014. References [1] R.C. Turner, P.A. Fuierer, R.E. Newnham, T.R. Shrout, Appl. Acoust. 41 (1994) 299–324. [2] R.E. Eitel, C.A. Randall, T.R. Shrout, P.W. Rehrig, W. Hackenberger, S.E. Park, Jpn. J. Appl. Phys. Part 1 40 (2001) 5999–6002. [3] R.E. Eitel, C.A. Randall, T.R. Shrout, S.E. Park, Jpn. J. Appl. Phys. Part 1 41 (2002) 2099–2104. [4] R.E. Eitel, S.J. Zhang, T.R. Shrout, C.A. Randall, I. Levin, J. Appl. Phys. 96 (2004) 2828–2831. [5] Y. Shimojo, R. Wang, T. Sekiya, T. Nakamura, L.E. Cross, Ferroelectrics 284 (2003) 121–128. [6] Y. Inaguma, A. Miyaguchi, M. Yoshida, T. Katsumata, Y. Shimojo, R. Wang, et al., J. Appl. Phys. 95 (2004) 231–235. [7] T.Y. Chen, S.Y. Chu, S.J. Wu, Y.D. Juang, Sens. Actuators, A, Phys. 101 (2002) 352–357. [8] L. Amarande, C. Miclea, C. Tanasoiu, J. Eur. Ceram. Soc. 22 (2002) 1269–1275. [9] P. Duran, J.F. Fernandez, C. Moure, J. Mater. Sci. Lett. 10 (1991) 917–919. [10] C.M. Beck, N.W. Thomas, I. Thompson, J. Eur. Ceram. Soc. 18 (1998) 1685–1693. [11] T. Zhou, W. Peng, X. Shang, K. Zheng, A. Kuang, Ferroelectrics 263 (2001) 297–302. [12] B. Jaffe, W.R. Cook, H. Jaffe, Piezoelectric Ceramics, Academic Press, Marietta, Ohio, 1971. [13] T.Y. Chen, S.Y. Chu, Y.D. Juang, Sens. Actuators, A, Phys. 102 (2002) 6–10. [14] S. Zhang, R. Xia, L. Lebrun, D. Anderson, T.R. Shrout, Mater. Lett. 59 (2005) 3471–3475. [15] S. Ikegami, I. Ueda, T. Nagata, J. Acoust. Soc. Am. 50 (1971) 1060–1066. [16] D. Damjanovic, T.R. Gururaja, L.E. Cross, Am. Ceram. Soc. Bull. 66 (1987) 699–703. [17] S. Zhang, R.E. Eitel, C.A. Randall, T.R. Shrout, E.F. Alberta, Appl. Phys. Lett. 86 (2005) 262904.