Structure Identification and Electrical Properties of the New Pyrochlore Phase in the Sr–Bi–Ta–Ti–O System

2000 ◽  
Vol 39 (Part 1, No. 9B) ◽  
pp. 5573-5576 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Bu-Kuan Fang ◽  
Cheng-Yen Wen
Keyword(s):  
Electrical Properties ◽  
Pyrochlore Phase ◽  
Structure Identification

Ferroelectric thin films with complex composition of PNN–PZN–PMN–PZ–PT and excess NiO

2008 ◽  
Vol 23 (2) ◽  
pp. 536-542 ◽  
Author(s):  
Phoi Chin Goh ◽  
Kui Yao ◽  
Zhong Chen
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Oxide System ◽  
Ferroelectric Thin Films ◽  
Ionic Radii ◽  
Pt Complex ◽  
The Stability

Ferroelectric thin films of the 0.1Pb(Ni1/3Nb2/3)O3–0.35Pb(Zn1/3Nb2/3)O3–0.15Pb (Mg1/3Nb2/3)O3–0.1PbZrO3–0.3PbTiO3 (PNN–PZN–PMN–PZ–PT) complex oxide system were prepared on Pt/Ti/SiO2/Si substrates using a polymer-modified sol-gel method followed by a rapid thermal annealing (RTA) process. It was found that the addition of excess NiO is effective in stabilizing the perovskite phase while suppressing the pyrochlore phase. The crystalline structure and morphology of the films with different amounts of access NiO were studied with x-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The electrical properties, including dielectric, ferroelectric, and piezoelectric, showed a significant improvement with excess NiO. The film sample with 3 mol% of excess NiO exhibited optimized electrical properties. Different parameters, including tolerance factors on the basis of ionic radii, electronegativity differences between cations and anions, and oxygen bond valences, were applied to analyze the stability of the perovskite phase with different amount of excess NiO. Analysis results indicated that only the bond-valence theory could explain the effect of excess NiO on the stability of the perovskite phase under the assumption that the excess Ni2+ entered the A sites of the perovskite structure.

Low Temperature Crystallization of Bismuth Layer-Structured Ferroelectric Thin Films Using Lead Titanate Sol-Gel Templating Technique and Their Electrical Properties

2003 ◽  
Vol 784 ◽  
Author(s):  
Junichi Karasawa ◽  
Takeshi Kijima ◽  
Eiji Natori ◽  
Tatsuya Shimoda
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Layered Structure ◽  
Crystallization Temperature ◽  
Lead Titanate ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Doping Amount ◽  
Gel Network

ABSTRACTThe crystal structure and electrical properties of lead titanate (PbTiO3: PT) sol-gel network templated bismuth layer-structured ferroelectric (BLSF) thin films were systematically investigated as a function of the doping amount of lead titanate sol-gel solution and annealing temperature. The starting solutions of lead titanate sol-gel templated BLSF were prepared by adding lead titanate sol-gel solution to BLSF solutions such as strontium bismuth tantalate (SrBi2Ta2O9: SBT), bismuth titanate (Bi4Ti3O12: BiT) and lanthanum-doped bismuth titanate ((Bi,La)4Ti3O12: BLT). These solutions were spin-coated on platinized silicon wafers and pyrolized on a hot plate, then crystallized at 550°C – 738°C by RTA (Rapid Thermal Annealing). The crystallized films with sputtered platinum top electrodes were post-annealed for electrical property measurements. In the case of SBT-PT, it was found that the added lead titanate so-gel network has no remarkable effect on lowering the BLSF (m=2) crystallization temperature but rather enhances the pyrochlore phase. In the case of BiT-PT, the bismuth layered-structure was confirmed at the temperature down to 550°C as the amount of lead titanate sol-gel network is increased. The major layered-structure, however, was not desired m=3, but unexpected m (e.g m=4 or higher). In the case of BLT-PT, lowering the BLSF (m=3) crystallization temperature down to 638°C was finally achieved within proper amount of lead titanate sol-gel network without drastic drop of ferroelectricity. A 2Pr of 32 μC/cm2 was obtained in 0.96BLT-0.04PT thin film.

scholarly journals Preparation features and electrical properties of Na0.5Bi0.5TiO3 thin films

2020 ◽  
Vol 28 (1) ◽  
pp. 33-38
Author(s):  
T. V. Kruzina ◽  
S. A. Popov ◽  
Yu. N. Potapovich ◽  
S. I. Ryabtsev ◽  
A. S. Rutskiy
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Electric Field ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Ex Situ ◽  
Structural Defects ◽  
Leakage Currents ◽  
Si Substrates ◽  
Film Substrate

Some special features of Na0.5Bi0.5TiO3 (NBT) thin films preparation process and electrical properties of the films are presented. The NBT films were grown on both Pt/sitall and Pt/TiO2/SiO2/Si substrates by ex-situ method with high-frequency (13.56 MHz) magnetron deposition. Thermal treatment of the films was carried out in the temperature range 550°С – 700°С in air. Obtained X-ray diffraction data show that annealing at 700°C promotes crystallization of NBT films in ferroelectric perovskite phase with minor inclusions of pyrochlore phase. Dielectric hysteresis (P-E) loops in electric field of 90 kV/cm (50 Hz) and the current density-electric field (J-E) characteristics of the films are investigated. It is found that densities of leakage currents in weak fields depend on the film substrate and are significantly lower for the films deposited on the Pt/sitall structure (~6.9 10-10 A/cm2) in comparison with the films deposited on the Pt/TiO2/SiO2/Si structure (~10-6 A/cm2). The main mechanisms of leakage currents in thin NBT ferroelectric films and the role of structural defects in charge transfer process are discussed.

Study on the Microstructure and Electrical Properties of Pb(Zr0.53 Ti0.47)O3 Thin-Films

2010 ◽  
Vol 644 ◽  
pp. 97-100 ◽  
Author(s):  
Leo A. Baldenegro-Perez ◽  
Wardia Debray-Mechtaly ◽  
E. Fuentes-Fernandez ◽  
M.A. Quevedo-López ◽  
Husam N. Alshareef ◽  
...  
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Complete Analysis ◽  
Electrical Measurements ◽  
Granule Formation ◽  
Large Size ◽  
Layered Thin Film

In the present study a complete analysis of the morphological and electrical properties of PZT layers with composition 53Zr-47Ti is presented. Three different samples composed of 3, 6, and 9 PZT layers were analyzed on a substrate consisting of ZrO2-SiO2-Si structures. The PZT and ZrO2 layers were deposited via Sol-Gel, whereas the SiO2 layer, on every sample, was deposited via PECVD. SEM results showed morphology of very small granules on the 3 layered thin-film samples (12 nm), on the 6 layered thin-film samples a mixture of small and large size (100-300 nm) granule formation was observed, with the 9 layered thin-film samples exhibiting very large granule sizes (bigger than 300 nm). XRD results showed that increasing the number of deposited layers caused an incremental increase on the detected peak intensities, aided in the promotion of the perovskite phase, and diminished the presence of the pyrochlore phase. It was also observed, during electrical measurements, that increasing the number deposited layers directly increased the overall capacitance of the thin-film structure. This effect was attributed primarily to the large amount of perovskite and large size of grains presented on thick samples.

Effect of Doping Nb2O5 on Microstructure and Properties of Piezoelectric Ceramics PSZT

2012 ◽  
Vol 217-219 ◽  
pp. 1182-1185 ◽  
Author(s):  
Ling Peng ◽  
Qi Bin Liu
Keyword(s):  
Crystal Structure ◽  
Crystal Growth ◽  
Solid State ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Piezoelectric Properties ◽  
Ceramic Powder ◽  
Pyrochlore Phase ◽  
Piezoelectric Ceramics ◽  
Solid State Sintering

o improve the electrical properties of PSZT piezoelectric ceramics, a ceramic powder Pb0.94Sr0.06(Zr0.52Ti0.48)O3 (PSZT) with Nb2O5 was designed. The power was prepared by solid state sintering. The surface structure of sample was characterized using SEM, and the crystal structure of the sample was examined by XRD. The capacitance and dielectric loss of sample was measured by Tonghui Electronics TH2618 capacitor tester. The result of microstructure and electrical properties show that Nb2O5 inhibit crystal growth when the contents of Nb2O5 is less than 0.5.wt%, but excessive Nb2O5 cause pyrochlore phase producing while the contents of Nb2O5 more than 0.5wt.% . The excellent piezoelectric properties are achieved in the ceramics with 0.5wt.% Nb2O5:εr=1504,tanδ=0.0065,d33=336pC/N, kp=0.562.

Influence of Pr6O11 on the Characteristics and Microstructure of Zinc Varistors

2008 ◽  
Vol 368-372 ◽  
pp. 500-502 ◽  
Author(s):  
Jian Feng Zhu ◽  
Ji Qiang Gao ◽  
Fen Wang ◽  
Ping Chen
Keyword(s):  
Electrical Properties ◽  
Grain Growth ◽  
Leakage Current ◽  
Threshold Voltage ◽  
Spinel Phase ◽  
Nonlinear Coefficient ◽  
Pyrochlore Phase ◽  
Voltage Ratio ◽  
Zno Crystal ◽  
Microstructural Homogeneity

The influence of the amount of Pr6O11 additions on the microstructure and electrical properties of varistors ceramics in the ZnO-Bi2O3 system was investigated. Samples with a low level of Pr6O11 (0.1wt %) have high microstructural homogeneity, which enhances the nonlinear coefficient greatly, and decreases the leakage current without change of voltage ratio. When the Pr6O11 content reached 7wt%, the ZnO grain growth was restricted and the threshold voltage was improved from 275v/mm to 440v/mm. The additive of Pr6O11 changed the process of creating spinel phase, which came from the decomposition of pyrochlore phase. This type of small size phase has more dragging force on the ZnO crystal, which make the whole materials more uniform and compact.

Structural and Electrical Properties of Ca2+ Substituted Pb[(Zr0.52Ti0.48)0,98(Cr3+0.5, Ta5+0.5)0,02]0,96 P0,04 O3 Ceramics

2014 ◽  
Vol 87 ◽  
pp. 18-23
Author(s):  
Louanes Hamzioui ◽  
Fares Kahoul ◽  
Ahmed Boutarfaia
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Rhombohedral Phase ◽  
Dissipation Factor ◽  
Sintering Behavior ◽  
Practical Applications ◽  
Low Dissipation ◽  
High Dielectric

Pb1-xCax[(Zr0.52Ti0.48)0,98(Cr3+0.5, Ta5+0.5)0,02]0,96P0,04O3(x = 0,00, 0.02, 0.04, 0.06) ceramics were prepared using the conventional mixed-oxide route. The resultant samples were sintered at different temperatures and subsequently characterized in terms of both microstructure and dielectric properties to study the effects of sintering behavior. X-ray diffraction analysis reveals that all specimens are a pure perovskite phase without pyrochlore phase and exhibits a phase transition from a rhombohedral phase to the coexistence of rhombohedral and tetragonal phases with an increase of sintering temperature. The grain size first increases up tox= 0.02 and then decreases. Comparing with the undoped ceramics, the dielectric properties of the Ca-doped PZT–PCTP specimens are significantly improved. The results show that the ceramics sintered at 1180°C have optimum electrical properties for x= 0.02: a high dielectric constant (εr= 16800) at Tc, a low dissipation factor (tanδ = 0.009) and a low resistivity (ρ= 0.09 ×10+4) (Ω.cm) at 1 kHz, which indicates that the PZT–CCTP ceramics are promising for lead practical applications.

Effects of La-Doping on Phase Structure and Electrical Properties of Pb(Mg1/3Nb2/3)0.67Ti0.33O3 Ceramic

2012 ◽  
Vol 622-623 ◽  
pp. 767-770
Author(s):  
Yong Liu ◽  
Rui Qing Chu ◽  
Zhi Jun Xu ◽  
Shu Ting Wang ◽  
Qing Bin Chi ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Phase Structure ◽  
Doping Level ◽  
Raw Materials ◽  
Pyrochlore Phase ◽  
X Ray Diffraction ◽  
La Doping ◽  
Low X ◽  
Sintering Method ◽  
La Doped

La-doped Pb(Mg1/3Nb2/3)0.67Ti0.33O3 ceramics were fabricated by a two-stage sintering method from conventional raw materials. The effects of La doping on the phase structure and electrical properties of ceramics were investigated. X-ray diffraction analysis showed that the pyrochlore phase increased with the increase of La-doping level. The effects of La doping on the dielectric, ferroelectric and piezoelectric properties of the ceramics were also investigated. The results showed that La doping seriously weakened the electrical properties of the ceramics. The ceramics possess optimum properties (d33=239pC/N, Pr=10.6μC/cm2, Ec=8.5kV/cm, tanδ=0.029, εr = 2250) when the doping level is low (x = 0.02).

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