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Guozhong Zang - One of the best experts on this subject based on the ideXlab platform.
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large piezoelectric coefficient in ba1 xcax ti0 96sn0 04 o3 lead free ceramics
Journal of the American Ceramic Society, 2011Co-Authors: Zhijun Xu, Peng Fu, Guozhong ZangAbstract:Lead-free (Ba1−xCax)(Ti0.96Sn0.04)O3 (BCST) (x = 0–0.04) ceramics were prepared using solid-state reaction technique. At room temperature, a polymorphic phase transition from orthorhombic phase to tetragonal phase was identified in the composition range of 0.01 ≤ x ≤ 0.03. Extremely high piezoelectric coefficient of d33 = 510 pC/N and high planar Electromechanical Coupling Factor of kp = 48% were obtained for the BCST ceramics at x = 0.02. These results indicate that the BCSTs are promising candidates for the widely used lead-based piezoelectric materials.
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temperature stability in dy doped ba0 99ca0 01 ti0 98zr0 02 o3 lead free ceramics with high piezoelectric coefficient
Journal of the American Ceramic Society, 2011Co-Authors: Zhijun Xu, Peng Fu, Guozhong ZangAbstract:We report on excellent temperature stability of the Dy-doped (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 (BCZT-D) ceramics with high piezoelectric coefficient of d33 = 366 pC/N and planar Electromechanical Coupling Factor of kp = 43.0%. Meanwhile, Curie temperature of the BCZT-D ceramics is found to be 125°C. Greatly improved temperature stability of the Electromechanical Coupling coefficients is found over a common usage temperature range between 20°C and 100°C, in which the BCZT-D ceramics exhibit pure tetragonal phase. The results indicate that the BCZT-D ceramics are promising lead-free materials for practical applications.
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high piezoelectric d33 coefficient in ba1 xcax ti0 98zr0 02 o3 lead free ceramics with relative high curie temperature
Materials Letters, 2010Co-Authors: Ruiqing Chu, Guozhong ZangAbstract:Lead-free (Ba1 − xCax)(Ti0.98Zr0.02)O3 (x = 0–0.04) ceramics were prepared successfully using a solid-state reaction technique. The polymorphic phase transitions (PPT) from orthorhombic to tetragonal phase around room temperature were identified in the composition range of 0 < x < 0.03. High piezoelectric coefficient of d33 = 375 pC/N and planar Electromechanical Coupling Factor of kp = 44.1% were obtained for the samples at x = 0.01. With the increase of Ca content, the orthorhombic–tetragonal phase transitions shifted towards room temperature, while relative high Curie temperature (TC) was still maintained about 115 °C.
Toshio Ogawa - One of the best experts on this subject based on the ideXlab platform.
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characterization and application of pb zn1 3nb2 3 0 91ti0 09 o3 single crystal with giant Electromechanical Coupling Factor k31
Ceramic transactions, 2012Co-Authors: Toshio OgawaAbstract:Giant Electromechanical Coupling Factor on length-extensional mode (k 31 ) over 85% and piezoelectric d 31 constant nearly -2100 pC/N were realized in (100) Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 (PZNT91/09) single-crystal plates poled along [001] of the original cubic direction in addition to the Coupling Factor on thickness longitudinal-extensional mode (k 33 ) nearly 95%. Furthermore, the giant k 31 showed excellent aging characteristics at room temperature, while the k 31 (59%) in (110) PZNT91/09 single-crystal plates decreased with time. This phenomenon could be explained by the relationship between the directions of the spontaneous polarization axes and the poling field. From the frequency responses of impedance, there were two kinds of the length-extensional vibration modes of k 31 (13 L mm) and k 32 (4 W mm). The frequency constants (fc) of these modes consisted of low and high fc of 520 kHz-m and 830 kHz-m, respectively. The response with the giant k 31 over 80% was composed of the low fc on k 31 mode and the high fc on k 32 mode, which are caused by the anisotropy of the crystal symmetry. PZNT91/09 single-crystal plates with giant k 31 over 80% were applied to piezoelectric unimorphs and series-type bimorphs. The Coupling Factors on bending mode (kb) were 64.7% (PZNT91/09 single crystal: k 31 =86.2%, d 31 =1890 pC/N) and 20.6% (PZT ceramics: k 31 =37.3%, d 31 =-330 pC/N) in unimorphs. The values of the kb in bimorphs were 69.6% (PZNT91/09 single crystal) and 31.2% (PZT ceramics). The displacement of the single-crystal devices showed excellent characteristics in comparison with the one of the PZT ceramic devices.
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Advances in Dielectric Materials and Electronic Devices - Characterization and Application of Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Single Crystal with Giant Electromechanical Coupling Factor k31
Ceramic Transactions Series, 2012Co-Authors: Toshio OgawaAbstract:Giant Electromechanical Coupling Factor on length-extensional mode (k 31 ) over 85% and piezoelectric d 31 constant nearly -2100 pC/N were realized in (100) Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 (PZNT91/09) single-crystal plates poled along [001] of the original cubic direction in addition to the Coupling Factor on thickness longitudinal-extensional mode (k 33 ) nearly 95%. Furthermore, the giant k 31 showed excellent aging characteristics at room temperature, while the k 31 (59%) in (110) PZNT91/09 single-crystal plates decreased with time. This phenomenon could be explained by the relationship between the directions of the spontaneous polarization axes and the poling field. From the frequency responses of impedance, there were two kinds of the length-extensional vibration modes of k 31 (13 L mm) and k 32 (4 W mm). The frequency constants (fc) of these modes consisted of low and high fc of 520 kHz-m and 830 kHz-m, respectively. The response with the giant k 31 over 80% was composed of the low fc on k 31 mode and the high fc on k 32 mode, which are caused by the anisotropy of the crystal symmetry. PZNT91/09 single-crystal plates with giant k 31 over 80% were applied to piezoelectric unimorphs and series-type bimorphs. The Coupling Factors on bending mode (kb) were 64.7% (PZNT91/09 single crystal: k 31 =86.2%, d 31 =1890 pC/N) and 20.6% (PZT ceramics: k 31 =37.3%, d 31 =-330 pC/N) in unimorphs. The values of the kb in bimorphs were 69.6% (PZNT91/09 single crystal) and 31.2% (PZT ceramics). The displacement of the single-crystal devices showed excellent characteristics in comparison with the one of the PZT ceramic devices.
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Giant Transverse-Mode Electromechanical Coupling Factor and Piezoelectric Strain in Relaxor Single-Crystal Plates Evaluated Using P-E Hysteresis Loop
Japanese Journal of Applied Physics, 2008Co-Authors: Toshio OgawaAbstract:The relationships between the giant piezoelectricity of transverse-mode Electromechanical Coupling Factor k31 and longitudinal-mode Electromechanical Coupling Factor k33 were studied in the cases of Pb[(Zn1=3Nb2=3)0:91Ti0:09]O3 (PZNT91/ 09) with (100) plane and (1 � x)Pb(Mg1=3Nb2=3)O3–xPbTiO3 [PMNT(1 � x)/x ]( x ¼ 0:251{ 0:301) with (110) plane. From the P–E hysteresis loops and the electric field (E) vs strain measurement, a triple hysteresis loop was observed in PZNT91/09, and triple hysteresis and asymmetric hysteresis loops were obtained in x ¼ 0:273 { 0:293 and x ¼ 0:251{ 0:262 in PMNT(1 � x)/x, while the giant k31 was realized in the relaxor single crystals. Furthermore, the E required to observe the triple and asymmetric loops corresponded to the E of a break in the line for E vs strain. It was considered that the E was a coercive field to generate the DC-field-induced phase transition with giant k31. [DOI: 10.1143/JJAP.47.7655]
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Ferroelectric Domain Controlled Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 Single Crystal with Giant Electromechanical Coupling Factor of k 31 Mode and Piezoelectric d 31 Constant
Ferroelectrics, 2003Co-Authors: Toshio Ogawa, Yoshiki NumamotoAbstract:Temperature and poling field dependences of the properties of large high-quality piezoelectric single crystals of Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 (PZNT91/09) grown by the Bridgman method were measured. The single crystals poled along [001] of the original cubic direction possess giant Electromechanical Coupling Factor k 31 over 80% and piezoelectric d 31 constant nearly m 1700 pC/N. These giant k 31 and d 31 constants results from the control of ferroelectric domain configuration. PZNT91/09 multi-domain single crystal became single-domain in the directions parallel and perpendicular to the poling field resulting in the appearance of giant k 31 and d 31 .
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Origin of Giant Electromechanical Coupling Factor of k31 Mode and Piezoelectric d31 Constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Single Crystal.
Japanese Journal of Applied Physics, 2002Co-Authors: Toshio Ogawa, Yoshiki NumamotoAbstract:The origin of the giant Electromechanical Coupling Factor of the k31 mode and piezoelectric d31 constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 single crystals was clarified to investigate the poling field dependences of their ferroelectric properties and domain structures. While the highest k33 of over 90% and d33 of nearly 2500 pC/N were obtained at the poling field of E1000 V/mm, the giant k31 of over 80% and -d31 of nearly 1700 pC/N were obtained at 1000 kV/mmE
Zhijun Xu - One of the best experts on this subject based on the ideXlab platform.
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large piezoelectric coefficient in ba1 xcax ti0 96sn0 04 o3 lead free ceramics
Journal of the American Ceramic Society, 2011Co-Authors: Zhijun Xu, Peng Fu, Guozhong ZangAbstract:Lead-free (Ba1−xCax)(Ti0.96Sn0.04)O3 (BCST) (x = 0–0.04) ceramics were prepared using solid-state reaction technique. At room temperature, a polymorphic phase transition from orthorhombic phase to tetragonal phase was identified in the composition range of 0.01 ≤ x ≤ 0.03. Extremely high piezoelectric coefficient of d33 = 510 pC/N and high planar Electromechanical Coupling Factor of kp = 48% were obtained for the BCST ceramics at x = 0.02. These results indicate that the BCSTs are promising candidates for the widely used lead-based piezoelectric materials.
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temperature stability in dy doped ba0 99ca0 01 ti0 98zr0 02 o3 lead free ceramics with high piezoelectric coefficient
Journal of the American Ceramic Society, 2011Co-Authors: Zhijun Xu, Peng Fu, Guozhong ZangAbstract:We report on excellent temperature stability of the Dy-doped (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 (BCZT-D) ceramics with high piezoelectric coefficient of d33 = 366 pC/N and planar Electromechanical Coupling Factor of kp = 43.0%. Meanwhile, Curie temperature of the BCZT-D ceramics is found to be 125°C. Greatly improved temperature stability of the Electromechanical Coupling coefficients is found over a common usage temperature range between 20°C and 100°C, in which the BCZT-D ceramics exhibit pure tetragonal phase. The results indicate that the BCZT-D ceramics are promising lead-free materials for practical applications.
Yoshiki Numamoto - One of the best experts on this subject based on the ideXlab platform.
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Ferroelectric Domain Controlled Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 Single Crystal with Giant Electromechanical Coupling Factor of k 31 Mode and Piezoelectric d 31 Constant
Ferroelectrics, 2003Co-Authors: Toshio Ogawa, Yoshiki NumamotoAbstract:Temperature and poling field dependences of the properties of large high-quality piezoelectric single crystals of Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 (PZNT91/09) grown by the Bridgman method were measured. The single crystals poled along [001] of the original cubic direction possess giant Electromechanical Coupling Factor k 31 over 80% and piezoelectric d 31 constant nearly m 1700 pC/N. These giant k 31 and d 31 constants results from the control of ferroelectric domain configuration. PZNT91/09 multi-domain single crystal became single-domain in the directions parallel and perpendicular to the poling field resulting in the appearance of giant k 31 and d 31 .
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Origin of Giant Electromechanical Coupling Factor of k31 Mode and Piezoelectric d31 Constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Single Crystal.
Japanese Journal of Applied Physics, 2002Co-Authors: Toshio Ogawa, Yoshiki NumamotoAbstract:The origin of the giant Electromechanical Coupling Factor of the k31 mode and piezoelectric d31 constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 single crystals was clarified to investigate the poling field dependences of their ferroelectric properties and domain structures. While the highest k33 of over 90% and d33 of nearly 2500 pC/N were obtained at the poling field of E1000 V/mm, the giant k31 of over 80% and -d31 of nearly 1700 pC/N were obtained at 1000 kV/mmE
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origin of giant Electromechanical Coupling Factor of k31 mode and piezoelectric d31 constant in pb zn1 3nb2 3 0 91ti0 09 o3 single crystal
Japanese Journal of Applied Physics, 2002Co-Authors: Toshio Ogawa, Yoshiki NumamotoAbstract:The origin of the giant Electromechanical Coupling Factor of the k31 mode and piezoelectric d31 constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 single crystals was clarified to investigate the poling field dependences of their ferroelectric properties and domain structures. While the highest k33 of over 90% and d33 of nearly 2500 pC/N were obtained at the poling field of E1000 V/mm, the giant k31 of over 80% and -d31 of nearly 1700 pC/N were obtained at 1000 kV/mmE<1500 kV/mm. Moreover, the frequency constant of k31 mode (fc31) showed the lowest value of nearly 500 Hzm in the same E range. The as-grown single crystal with multidomains, which were observed under polarized light, changed to reveal several domains oriented in the direction of the poling field. With increasing E to 1000 V/mm, the domains oriented in the direction of the poling field changed into a monodomain oriented in the direction perpendicular to the poling field as well as in the direction parallel to the poling field. The monodomain crystal controlled by the specific poling fields of 1000 V/mmE<1500 V/mm showed the giant k31 and the d31 constant. With extended application of E over 1500 V/mm, k31 and d31 decreased abruptly because the monodomain changed into a number of domains in the crystal.
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Giant Electromechanical Coupling Factor of k31 Mode and Piezoelectric d31 Constant in Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Piezoelectric Single Crystal
Japanese Journal of Applied Physics, 2002Co-Authors: Toshio Ogawa, Yoshiki Numamoto, M. Matsushita, Yoshiaki Yamauchi, Yoshihito TachiAbstract:High-quality and large piezoelectric single crystals of Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 (PZNT91/09) fabricated by the Bridgman method were investigated regarding the material constants and their temperature dependence. The single crystals poled along [001] of the original cubic direction possess high piezoelectric constants such as g33 and g31 as well as high dielectric constant e33T/e0 (4600), Electromechanical Coupling Factor of the k33 mode (95.3%) and d33 (2500 pC/N). In particular, since k31 and d31 reach 80.8% and -1700 pC/N, respectively, the crystals can be applied for use in sensors and actuators with high performance. Based on the temperature dependence, we inferred that there is a relatively large difference in the elastic compliance (s11E) between rhombohedral and tetragonal phases. The cause of the high piezoelectricity in rhombohedral PZNT91/09 single crystals is thought to be the mechanical softness which leads to easy deformation by the poling field in comparison with the tetragonal phase.
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giant Electromechanical Coupling Factor of k31 mode and piezoelectric d31 constant in pb zn1 3nb2 3 0 91ti0 09 o3 piezoelectric single crystal
Japanese Journal of Applied Physics, 2002Co-Authors: Toshio Ogawa, Yoshiki Numamoto, M. Matsushita, Yoshiaki Yamauchi, Yoshihito TachiAbstract:High-quality and large piezoelectric single crystals of Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 (PZNT91/09) fabricated by the Bridgman method were investigated regarding the material constants and their temperature dependence. The single crystals poled along [001] of the original cubic direction possess high piezoelectric constants such as g33 and g31 as well as high dielectric constant e33T/e0 (4600), Electromechanical Coupling Factor of the k33 mode (95.3%) and d33 (2500 pC/N). In particular, since k31 and d31 reach 80.8% and -1700 pC/N, respectively, the crystals can be applied for use in sensors and actuators with high performance. Based on the temperature dependence, we inferred that there is a relatively large difference in the elastic compliance (s11E) between rhombohedral and tetragonal phases. The cause of the high piezoelectricity in rhombohedral PZNT91/09 single crystals is thought to be the mechanical softness which leads to easy deformation by the poling field in comparison with the tetragonal phase.
Zhenghua Qia - One of the best experts on this subject based on the ideXlab platform.
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transverse surface waves in functionally graded piezoelectric materials with exponential variation
Smart Materials and Structures, 2008Co-Authors: Zhenghua Qia, Kikuo KishimotoAbstract:For a functionally graded piezoelectric substrate with exponential variation, the existence and propagation behavior of transverse surface waves is studied by analytical technique. The dispersion equations for the existence of the transverse surface waves with respect to phase velocity are obtained for both electrically open and short conditions. A detailed investigation of the effect of gradient coefficient on dispersion relation, phase velocity, group velocity and Electromechanical Coupling Factor is carried out. It is found by numerical examples that adjusting gradient coefficient makes the Electromechanical Coupling Factor of the transverse surface waves achieve quite high values at some appropriate wavenumber, and at the same time, the penetration depth can be reduced to the same order as the wavelength under electrically short case. Because of the negligible initial stress in functionally graded piezoelectric materials, this model could serve as an excellent substitute for the typical layered piezoelectric structures used in surface acoustic wave (SAW) devices, thus providing a theoretical foundation for designing SAW devices with high performance.