Structural and Electrical Properties of Lead Zirconate Titanate [Pb(ZrxTi1-x)O3] Ceramics (original) (raw)
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Powders wet-chemically synthesized by the " oxidant-peroxo method " with PbZr 05 Ti 0.5 O 3 composition were sintered at 1000 and 1100° C for 2 and 4 h, resulting in dense ceramic bodies that were structurally characterized by Raman scattering spectroscopy and by x-ray diffraction at room temperature. Their electrical properties (dielectric constant and dielectric loss) were measured in the temperature range from 25 to 450° C at different current frequencies (1, 10, and 100 kHz). Microstructures were observed using a scanning electronic microscopy equipped with a x-ray energy dispersive spectrometer for chemical analysis. It was observed that the sintered bodies show tetragonal structure, and apparent densities calculated as 90% – 94% of the theoretical density.
A ternary system of lead niobate–lead zirconate–lead titanate with composition xPN–yPZ–(x-y)PT where í µí±¥ = 0.5 and í µí±¦ = 0.15, 0.25, and 0.35 known as PNZT has been prepared by conventional mixed oxide route at a temperature of 1100 ∘ C. The formation of the perovskite phase was established by X-ray diffraction analysis. The surface morphology studied by scanning electron microscopy shows the formation of fairly dense grains and elemental composition was confirmed by energy dispersive X-ray analysis. Dielectric properties like dielectric constant and dielectric loss (í µí¼ í® í° and tan í µí»¿) indicate poly-dispersive nature of the material. The temperature dependent dielectric constant (í µí¼ í® í°) curve indicates relaxor behaviour with two dielectric anomalies. The poly-dispersive nature of the material was analysed by Cole-Cole plots. The activation energy follows the Arrhenius law and is found to decrease with increasing frequency for each composition. The frequency dependence of ac conductivity follows the universal power law. The ac conductivity analysis suggests that hopping of charge carriers among the localized sites is responsible for electrical conduction. The ferroelectric studies reveal that these ternary systems are soft ferroelectric.
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.
Integrated Ferroelectrics, 2010
Polycrystalline ceramics samples having compositional formula PbZr0.588Ti0.392Fe0.01Nb0.01O3 and Pb0.98Sm0.02Zr0.588Ti0.392Fe0.01Nb0.01O3 were prepared by traditional solid state route. Sintering was carried out at 1250°C in closed alumina crucibles in lead rich atmosphere. XRD analysis confirmed formation of tetragonal perovskite structure and tetragonality was found to decrease with Sm substitution. In order to study microstructure, SEM micrographs were recorded on freshly broken pieces. The grain size was observed to decrease with Sm addition. P-E hysteresis loops were recorded at different temperatures for investigating ferroelectric properties. Sm substitution improves squareness and remanence.
A series of Lead Titanate ceramic with various concentration of Calcium has been prepared by solid state reaction method, and some of their physical properties and structural characteristics have been studied. The incorporation of small amount of Calcium results in considerable changes in the dc electrical conductivity and the temperature of the ferroelectric phase transition. Lead Titanate (PT) is a well known ferroelectric with high curie point and low dielectric thus constant making it an attractive proportion for various applications. The synthesis of Calcium modified PbTiO 3 was carried using solid state reaction method. Stoichiometric amount of high purity CaO was used as a dopant in different proportion and the final product was in powder form. The X-ray diffraction pattern was taken for pure and CaO modified Lead Titanate. The SEM of the sample was done on JEOL 6360A Analytical Scanning Electron Microscope. There is an observable change in grain size with different molar concentration of Calcium oxide. The DC conductivity of the sample was carried out using two probe method over a range of temperature covering their transition temperature.
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.
Dielectric properties of ceramics in lead zirconate titanate-lead magnesium niobate system
Songklanakarin J Sci Tech, 2004
Yimnirun, R., Ananta, S. and Laoratakul, P. Dielectric properties of ceramics in lead zirconate titanate -lead magnesium niobate system Songklanakarin J. Sci. Technol., 2004, 26(4) : 529-536 In this study, the xPb(Zr 0.52 Ti 0.48 )O 3 -(1-x)Pb(Mg 1/3 Nb 2/3 )O 3 (when x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) ceramic composites are prepared from PZT and PMN powders by a conventional mixed-oxide method. The dielectric properties of the ceramics are measured as functions of both temperature (-150 -400ºC) and frequency (100 Hz -1 MHz). The results indicate that the dielectric properties of the pure phase PZT and PMN are of normal and relaxor ferroelectric behaviors, respectively. The dielectric behaviors of the 0.9PZT -0.1PMN and 0.7PZT -0.3PMN ceramics are more of normal ferroelectrics, while the other compositions are obviously of relaxor ferroelectrics. In addition, the transition temperature decreases and the maximum dielectric constant increases with increasing PMN content in the system. These results clearly show the significance of PMN in controlling the dielectric behavior of the PZT-PMN system.
Journal of Applied Physics, 2009
The influence of the microstructural characteristics on the dielectric and electrical properties has been investigated for Nd3+ doped lanthanum modified lead zirconate titanate ferroelectric ceramics, obtained by the conventional solid-state reaction method, by taking into account different sintering conditions. The grain growth mechanism has been investigated and a cubic-type grain growth law was observed for samples with grain size varying from 1.00 up to 2.35 μm. The porosity and grain size dependences of the phase transition parameters, such as the maximum dielectric permittivity and its corresponding temperature (εm and Tm, respectively) were also investigated. The ac conductivity analyses followed the universal Jonscher law. The behavior of the frequency exponent (s) was analyzed through the correlated barrier hopping model. Both ac and dc conductivity results have been correlated with the observed microstructural features.
Dielectric and electrical properties of gadolinium-modified lead-zirconate-titanate system
Journal of Alloys and Compounds, 2014
The gadolinium (Gd) modified lead zirconate titanate (PbZr,TiO 3) ceramics with Zr/Ti = 48/52 (i.e., near morphotropic phase boundary (MPB)) in a general chemical formula Pb 1Àx Gd x (Zr 0.48 Ti 0.52) 1Àx/4 O 3 (PGZT; x = 0, 0.07, 0.10 and 0.12) have been synthesized using a high-temperature solid-state reaction method. Preliminary structural analysis using X-ray powder diffraction (XRD) shows the formation of a single-phase tetragonal structure of the compounds. Detailed studies of dielectric parameters of PGZT exhibit the diffuse phase transition but non-relaxor characteristics in the material for the higher concentration of gadolinium. The ac conductivity spectra of PGZT are found to obey Jonscher's universal power law. The electrical impedance parameters of PGZT (near MPB) were obtained in a wide range of temperature (25-500°C) and frequency (1-1000 kHz) using complex impedance spectroscopy (CIS) technique. Detailed analysis of these parameters shows that bulk (grain) and grain boundary resistance have significant effect on the total impedance of the materials. Temperature dependence of hysteresis characteristics of PGZT confirms that the phase transition parameter of the material is strongly affected by the substitution of Gd at the Pb-sites. Ó 2014 Elsevier B.V. All rights reserved. 2. Experimental 2.1. Sample preparation Lead monoxide (99% Loba Chemie Pvt. Ltd., India), titanium dioxide (99.5% Loba Chemie Pvt. Ltd., India), gadolinium trioxide (99.9% Loba Chemie Pvt. Ltd., India) and zirconium oxide (99%, Himedia Chemie Pvt. Ltd., India) were used to synthesize the required materials. The polycrystalline samples of Gd-modified lead zirconate titanate with a general formula Pb 1Àx Gd x (Zr 0.48 Ti 0.52) 1Àx/4 O 3 (PGZT) (x = 0, 0.07, 0.10 and 0.12) were prepared using a high-temperature solid-state reaction technique with the above oxides. Two-mole% of excess PbO was taken to compensate for Pb loss during high-temperature calcination and sintering. The ingredient (oxides) were mixed thoroughly; first in an air atmosphere for 1 h and then in wet (i.e., methanol) atmosphere for 2 h in agate mortar. The calcination temperature of the mixed samples was optimized (1100°C) based on repeated firing/mixing for 4 h