Effect of net PbO content on mechanical and electromechanical properties of lead zirconate titanate ceramics (original) (raw)
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Journal of the European Ceramic Society, 2007
In the present investigation we studied the effect of lead content on a hard type ceramics starting from lack to excess PbO. Specimens of Pb x (Mn 0.017 Sb 0.033 Zr 0.48 Ti 0.47)O 3 with 0.96 ≤ x ≤ 1.06 were prepared by conventional oxide mixing technique and sintered at temperatures between 1280 and 1350 • C. In samples with lower Pb concentration the pyrochlore phase appeared, while in those with higher Pb an excess of PbO phase was detected. These phases proved detrimental for the properties of sintered ceramics. The highest values of piezoelectric properties were observed only for samples with an excess lead of about 2% sintered at 1340 • C, indicating that it represents the optimum amount of PbO. For such samples, the density ρ was 7.77 g/cm 3 , the remnant polarization P r was 37 C/cm 3 the planar coupling coefficient k p was 0.57 and the charge constant d 33 was 340 pC/N.
Piezoelectric and mechanical properties of ceria-doped lead zirconate titanate ceramics
Journal of Materials Science, 1992
Phases, microstructures and properties of lead-zirconate-titanate (PZT) ceramics with the compositions Pb(Zro.535_~Ce~Tio.465)03 where 6 = 0.0, 0.001, 0.01, 0.02 and 0.05 were studied. Rhombohedral and tetragonal phases were present at 5-0.0. The amount of the rhombohedral phase increased with increasing 5, and only the tetragonal phase was present for 5 > 0.001. The c/a ratio of the tetragonal phase also increases with increasing 5. Particles of Ce02 were found to be present in compositions with 5 > 0.01, indicating that the solubility of CeO2 is less than 1 a/o on the metals basis. The piezoelectric and electromechanical constants achieved maximum values for 5-0.001. The hardness increased monotonically with increasing 6. The modulus of rupture and the fracture toughness, however, went through a minimum and both stayed lower than their values for 5-0.
Physica B: Condensed Matter, 2013
The perovskite Pb (1 À x) Ba x Zr 0.55 Ti 0.45 O 3 material (x ¼0.00, 0.01, 0.02, 0.03, 0.05, and 0.07) was synthesized by solid state reaction route. Green bodies were sintered at 1250 1C. All samples were subjected to X-ray diffraction analysis and they were found to be in single phase. Dielectric properties were studied as a function of temperature and frequency. Ferroelectric properties were studied as a function of temperature. Remnant polarization, saturation polarization and coercive field were determined for all the samples using ferroelectric loops. Piezoelectric properties such as d 33 and electromechanical coupling factor (k p) were also measured at room temperature for all samples.
Materials Science and Engineering: B, 2010
Lead zinc niobate-lead zirconium titanate, 0.3Pb(Zn 1/3 Nb 2/3)O 3-0.7Pb(Zr 0.51 Ti 0.49)O 3 (PZN-PZT), ceramics doped with different amounts of lanthanum (La) were prepared by mechano-chemical alloying (MCA) method accompanied by sintering. The results of X-ray diffraction suggest that all the ceramics crystallize into a single-phase pervoskite structure. The SEM analysis of the ceramic samples reveals a dense microstructure with homogeneous distribution of grains. The bulk density of the ceramics increases with the increase of La content. The effects of the La doping on the dielectric and piezoelectric properties of the ceramics were systematically examined. An increase in La concentration causes the Curie temperature (T c) to decrease and the phase transition to become more diffused. The piezoelectric charge coefficient (d 33) and electromechanical coupling constant (k p) show improvement with the increase of La doping level in the ceramic system. The d 33 , k p and percentage strain of the 3 mol%-La doped PZN-PZT ceramic were observed to be 575 pC/N, 64 and 22%, respectively.
The grain size dependence of high power piezoelectric properties and their variation upon heat generation for Nb doped lead zirconate titanate oxide (PZT)-based ceramics were investigated under high AC electric fields. The temperature rise was found to decrease linearly upon reduction in grain size and was about 40% lower for fine grained ceramic (0.9 µm) compared to coarse grained one (3.0 µm) near the maximum vibration velocity level (0.30 m/s) whereas coercive field displayed a linear increase upon lowering the grain size. Furthermore, a rise in vibration velocity and mechanical quality factor (Q m ) under low electric fields was found to correlate with decreasing grain size. Such a trend was explained in terms of the pinning effect of grain boundaries, which is observed to be critical for suppressing heat generation in high power ceramic applications.
Journal of Materials Science: Materials in Electronics, 2016
Lead zirconate titanate (PZT) based piezoelectric ceramics with a composition of (Pb 0.99-3x/2 La x) (Zr 0.95 Ti 0.05) 0.98 Nb 0.02 O 3 where x = 0.0, 0.004, 0.005 and 0.006 were synthesized using conventional solid state sintering at 1250, 1275 and 1300°C. The effect of lanthanum substitution on the microstructure, dielectric and piezoelectric properties of the samples were studied. The results showed that lanthanum substitution was beneficial for densification of the samples during sintering and the samples with 0.6 mol% lanthanum exhibited the maximum density of 7.59 g/cm 3 when sintered at 1275°C. Moreover, the piezoelectric coefficients (d 33) and (d 31), voltage coefficients (g 33) and (g 31), relative dielectric constant (e r), dielectric loss (tand) and electromechanical coupling coefficient (k p) of the samples reached the optimal values of 70 and-15 PC/N, 25.50 9 10-3 and-5.36 9 10-3 Vm/m, 310, 0.025 and 0.163, respectively at 0.4 mol lanthanum substitution. Furthermore, the elastic compliances (S 11 E) and (S 12 E), the Poisson's ratio (r), The Young's modulus (Y 11 E), the sound velocity (v) and the mechanical quality factor (Q m) of the samples reached the optimal values of 7.93 and-2.01 9 10-12 m 2 /N, 0.2535 and 126 9 10 9 N/m 2 , 4079 m/s and 304, respectively for the same samples. The results indicate that the lanthanum doped PZTN ceramics can be hopefully used for pulsed power devices.
Structural and Electrical Properties of Lead Zirconate Titanate [Pb(ZrxTi1-x)O3] Ceramics
Lead Zirconate Titanate [PZT: Pb(ZrxTi1-x)O3; x = 0.40, 0.45, 0.55 and 0.60] ceramics were prepared by mixed oxide method at high temperature. Preliminary structural analysis through X-ray diffraction technique suggests about the formation of compounds at room temperature in tetragonal crystal system. Their tetragonality exhibits a decreasing trend with the increase in Zr4+ concentration. Micro structural analysis using SEM-microphotographs suggests that the grains are uniformly distributed on the surfaces of the samples with small porosity. Study of dielectric properties at different temperatures and frequencies exhibits high dielectric constant and low loss tangent along with the transition temperature well above the room temperature. The ferroelectric to paraelectric transition temperature in PZT samples exhibits a decreasing trend with the increase in Zr4+ concentration. Study of ac-conductivity at different temperatures and the value of activation energy in different regions suggest that the conduction process in the materials is of mixed type; singly ionized in ferroelectric region and doubly ionized in paraelectric region.
Journal of the American Ceramic Society, 2007
Lead zinc niobate-lead zirconate titanate (PZN-PZT) nanosized powders with a diameter of B35 nm were fabricated by a high-energy stirred media mill using 50 lm diameter zirconia beads as the milling media at a rotation speed of 4000 rpm for 1 h. The sintering temperature of PZN-PZT was greatly reduced, and a fully densified bulk body was obtained at only 7501C when stirred media milled nanopowder was used. The control of evaporation of lead oxide was very important to obtain high electrical properties due to the increased surface area of nano-sized powders. The ferroelectric hysteresis, piezoelectric d 33 coefficient, and dielectric properties of sintered ceramics using nanopowder were measured and compared with the values obtained from a sintered specimen using conventional milled powders. Remanent polarization, d 33 coefficient, and relative dielectric constant of 7501C sintered stirred media milled powders containing 2% of excess PbO and 1% of 4PbO-B 2 O 3 liquid phase were 10.3 lC/cm 2 , 277 pC/N, and 1310, respectively.
2004
The sintering behavior and piezoelectric properties of the lead zirconate titanate (Pb(Zr , Ti)O 3 , PZT)-lead zinc niobate (Pb(Zn 1/3 Nb 2/3 )O 3 , PZN) system were investigated. The sintering temperature required for full densification of the PZT-PZN system was significantly lowered when the proportion of PZN was increased. The density of the specimen composed of 60% PZT and 40% PZN (0.6PZT-0.4PZN, Pb((Zr 0.47 Ti 0.53 ) 0.6 -(Zn 1/3 Nb 2/3 ) 0.4 )O 3 ) sintered at 880°C for 4 h was 8.15 g/cm 3 , which was >97% of the theoretical value. This improved densification behavior was attributed to the combined effects of the high sinterability of PZN and the stability of the PZT perovskite structure. The piezoelectric and dielectric properties of the 0.6PZT-0.4PZN specimen sintered at 880°C were comparable with those of a specimen with the same composition sintered at 1200°C for 2 h. The piezoelectric coefficient (d 33 ) and the electromechanical coupling factor (k p ) of the 0.6PZT-0.4PZN specimen sintered at 880°C were 460 pC/N and 0.6, respectively.