scholarly journals Preparation, Structural, Electrical, and Ferroelectric Properties of Lead Niobate–Lead Zirconate–Lead Titanate Ternary System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Rashmi Gupta ◽  
Seema Verma ◽  
Vishal Singh ◽  
K. K. Bamzai

A ternary system of lead niobate–lead zirconate–lead titanate with composition xPN–yPZ–(x-y)PT where x=0.5 and y=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 (ε′ and tan⁡δ) indicate poly-dispersive nature of the material. The temperature dependent dielectric constant (ε′) 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.

2003 ◽  
Vol 18 (12) ◽  
pp. 2882-2889 ◽  
Author(s):  
Naratip Vittayakorn ◽  
Gobwute Rujijanagul ◽  
Tawee Tunkasiri ◽  
Xiaoli Tan ◽  
David P. Cann

The ternary system of lead nickel niobate Pb(Ni1/3Nb2/3)O3 (PNN), lead zinc niobate Pb(Zn1/3Nb2/3)O3 (PZN), and lead zirconate titanate Pb(Zr1/2Ti1/2)O3 (PZT) was investigated to determine the influence of different solid state processing conditions on dielectric and ferroelectric properties. The ceramic materials were characterized using x-ray diffraction, dielectric measurements, and hysteresis measurements. To stabilize the perovskite phase, the columbite route was utilized with a double crucible technique and excess PbO. The phase-pure perovskite phase of PNN–PZN–PZT ceramics was obtained over a wide compositional range. It was observed that for the ternary system 0.5PNN–(0.5 - x)PZN–xPZT, the change in the transition temperature (Tm) is approximately linear with respect to the PZT content in the range x [H11505] 0 to 0.5. With an increase in x, Tm shifts up to high temperatures. Examination of the remanent polarization (Pr) revealed a significant increase with increasing x. In addition, the relative permittivity ([H9280]r) increased as a function of x. The highest permittivities ([H9280]r [H11505] 22,000) and the highest remanent polarization (Pr [H11505] 25 μC/cm2) were recorded for the binary composition 0.5Pb(Ni1/3Nb2/3)O3–0.5Pb(Zr1/2Ti1/2)O3.


2021 ◽  
Vol 8 (3) ◽  
pp. 14-19
Author(s):  
Thuy Nguyen Thanh ◽  
Tung Nguyen Van ◽  
Hung Nguyen Trong ◽  
Minh Cao Duy

Lanthanum-doped lead zirconate titanate (PLZT) powders were synthesized using thehydrothermal method. The influence of pH, reaction temperature and time, lanthanum concentration on the formation and characteristics of PLZT were investigated. Obtained powders were investigated using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) techniques and a dielectric analyzer. The results showed that           Pb1-xLax(Zr0.65Ti0.35)O3 with x= 0.0 – 0.1 were well formed under conditions: pH≥13, reaction time of 12hrs, reaction temperature of 180oC. Dielectric constant of PLZT is higher than PZT. The grain size of the PLZT is found to be 1–3.5 µm.


2015 ◽  
Vol 9 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rashmi Gupta ◽  
Seema Verma ◽  
Deepa Singh ◽  
Karan Singh ◽  
Krishen Bamzai

The solid solutions of lead nickel niobate (PNN) and lead zirconate titanate (PZT), with general formula 0.5 Pb(NixNb1-x)O3-0.5 PZT, where x = 1/3, 1/2 and 2/3 and Zr/Ti = 50/50, were prepared by conventional solid state reaction technique. The perovskite phase formation and morphology were examined by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. From microstructure investigations, the grain size was found to lie in the range of 0.2-1.1 ?m. Diffuse phase transition and dielectric relaxation was obtained for all three compositions. The nature of dielectric relaxation was investigated through complex plane Argand plot or Cole-Cole plot. It was found that both grains as well as grain boundary contribute to dielectric relaxation. A direct correlation between the grain size and electrical properties was obtained. The remnant polarization and grain size were found to follow the inverse relationship. The inverse relationship between remnant polarization and grain size was established.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2396 ◽  
Author(s):  
Jinfa Liao ◽  
Hang Wang ◽  
Tzu-Yu Chen

The phase equilibrium of the Ni–Al–La ternary system in a nickel-rich region was observed at 800 °C and 1000 °C using scanning electron microscopy backscattered electron imaging, energy dispersive X-ray spectrometry and X-ray diffractometry. The solubility of Al in the Ni5La phase was remeasured at 800 °C and 1000 °C. Herein, we report a new ternary phase, termed Ni2AlLa, confirmed at 800 °C. Its X-ray diffraction (XRD) pattern was indexed and space group determined using Total Pattern Solution (TOPAS), and the suitable lattice parameters were fitted using the Pawley method and selected-area electron diffraction. Ni2AlLa crystallizes in the trigonal system with a space group R3 (no. 146), a = 4.1985 Å and c = 13.6626 Å. A self-consistent set of thermodynamic parameters for the Al–La and Ni–La binary systems and the Ni–Al–La ternary system includes a Ni2AlLa ternary phase, which was optimized using the CALPHAD method. The calculated thermodynamic and phase-equilibria data for the binary and ternary systems are consistent with the literature and measured data.


2006 ◽  
Vol 326-328 ◽  
pp. 613-616
Author(s):  
Dae Jin Yang ◽  
Seong Je Cho ◽  
Jong Oh Kim ◽  
Won Youl Choi

Lead zirconate titanate (Pb(Zr0.48Ti0.52)O3 or PZT) films were grown on platinized silicon wafers (Pt/SiO2/Si) by d.c. reactive sputtering method with multi targets. The Pb content of PZT films has been widely recognized as affecting not only the phase formation and microstructure but also the dielectric and ferroelectric properties. Pb content of PZT films was controlled by the variation of Pb target current. The relation between Pb content and Pb target current was expressed as y=0.89x-11.09. The x and y are Pb target current and Pb content, respectively. The pyrochlore phase was transformed to perovskite phase as Pb content was increased. This phase transformation improved the ferroelectric properties of PZT films. In PZT films with perovskite phase, fatigue properties were not improved with excess Pb content. Fatigue properties of PZT films began to be fatigued after 106 switching cycles and coincided with the typical PZT fatigue behavior. Excess Pb content (Pb vacancy) did not affect the fatigue properties of PZT films.


2011 ◽  
Vol 415-417 ◽  
pp. 1064-1069 ◽  
Author(s):  
Chia Ching Wu ◽  
Ying Hsun Lin ◽  
Ping Shou Cheng ◽  
Chao Chin Chan ◽  
Cheng Fu Yang

Perovskite-based (1-x) (Na0.5Bi0.5)TiO3-x NaNbO3 [(1-x) NBT-x NN, x = 0.1, 0.2, 0.3 and 0.4] ceramics were sintered at 1080°C. Dielectric characteristics, crystalline structures, and Raman investigations were carried out on (1-x) (Na0.5Bi0.5)TiO3-x NaNbO3 ceramics. X-ray diffraction (XRD) patterns showed that NaNbO3 ceramic would form a solid solution with (Na0.5Bi0.5)TiO3 ceramic, and and unknown or second phases were not observable as well. NaNbO3 ceramic diffused into the crystalline structure of (Na0.5Bi0.5)TiO3 ceramic and (1-x) NBT-x NN ceramics still revealed a rhombohedral structure. The temperature-dielectric constant curves showed that as NN content increased, the temperature to reveal the maximum dielectric constant (Tm) was raised, the depolarization temperature (Td) was shifted to lower value, and the dielectric constant at Tm and the loss tangent at Td gradually decreased. The Raman bands at 770 and 830 cm-1 were attributed to the existence of the oxygen vacancies. In this study, the relaxor-type ferroelectric properties of NBT ceramic had been improved as NN ceramic was added.


2015 ◽  
Vol 804 ◽  
pp. 21-24
Author(s):  
Ladapak Chumprasert ◽  
Narit Funsueb ◽  
Apichart Limpichaipanit ◽  
Athipong Ngamjarurojana

Barium titanate (BT) additive in lanthanum modified lead zirconate titanate (PLZT) was used to modify the microstructure and resultant properties of (1-x) PLZT– x BT where x= 0, 0.05, 0.10, 0.15, 0.20 and 0.25. Oxide powders were synthesized by mixed oxide synthetic route via a rapid vibro-milling technique. All of samples were sintered at 1275°C with the soaking time of 4 h. The ceramic samples were investigated for phase formation and evolution, dielectric behavior and ferroelectric properties. Introduction of BT in PLZT lattice resulted in ferroelectric tetragonal-rhombohedral structure, and further increase of BT content resulted in stabilizing the ferroelectric tetragonal perovskite phase. Dielectric behavior and ferroelectric properties were examined as a function of BT content.


2004 ◽  
Vol 811 ◽  
Author(s):  
Sonalee Chopra ◽  
Seema Sharma ◽  
T.C. Goel ◽  
R.G. Mendiratta

ABSTRACTFerroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.


2009 ◽  
Vol 421-422 ◽  
pp. 385-388
Author(s):  
Piyachon Ketsuwan ◽  
Anurak Prasatkhetragarn ◽  
Supon Ananta ◽  
Chien Chih Huang ◽  
David P. Cann ◽  
...  

The 3 mol% Nb2O5 doped Pb(Zr0.52Ti0.48)O3 with addition of 1-3 mol% Cr2O3 prepared via the solid-state reaction technique have been investigated. The XRD shows that a sample is primarily in both tetragonal and rhombohedral phases coexist and the amount of rhombohedral phase decreases that is due to the donor (Nb) dopant reduces the number of oxygen vacancies and leads to a lower amount of rhombohedral phase. The maximum dielectric constant tend to decrease with increasing Cr doping concentration from 0.1 to 1 mol%. Further increase in Cr concentration, the maximum dielectric constant increase dramatically. The hysteresis loop measurements, the electrical coercivity and the remnant polarization do not show a systematic trend at low concentration of Cr doping. It is possibly due to the partial solubility of Cr doping. The observations clearly indicate the hardening behavior at higher concentration because of more solubility of Cr.


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