scholarly journals Influence of the synthesis route on the properties of BNBT ceramics

2009 ◽  
Vol 3 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
Elisa Mercadelli ◽  
Alessandra Sanson ◽  
Claudio Capiani ◽  
Luisa Costa ◽  
Carmen Galassi
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Microstructural Properties ◽  
Barium Acetate ◽  
Mechanical Mixing ◽  
Chemical Route ◽  
Critical Comparison ◽  
Gel Combustion

BNBT (0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3) nanopowders were prepared starting from an aqueous solution of inorganic salts (barium acetate, bismuth nitrate, sodium nitrate and titanium isopropoxide) either by the citrate- nitrate sol-gel combustion (SGC) or by spray drying (SD). Their chemical and microstructural properties were compared with the ones of the same system obtained by mechanical mixing of oxides (SSCO). The SD and SGC powders require temperatures 150 and 300?C lower than SSCO powder to form the perovskite phase. The chemical and physical properties of the obtained powders strongly depend on the considered chemical route. Therefore the subsequent sintering step and consequently the microstructure of the obtained ceramics differ significantly. The microstructures as well the piezoelectric properties of the sintered SGC, SD, SSCO samples are investigated and a critical comparison is presented. .

scholarly journals Transferred PMN-PT Thick Film on Conductive Silver Epoxy

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1621 ◽  
Author(s):  
Tao Zhang ◽  
Jun Ou-Yang ◽  
Xiaofei Yang ◽  
Benpeng Zhu
Keyword(s):  
Thick Film ◽  
Silicon Substrate ◽  
Chemical Method ◽  
Piezoelectric Properties ◽  
Sol Gel ◽  
Wet Chemical Method ◽  
Chemical Route ◽  
Wet Chemical ◽  
Silver Epoxy ◽  
Ferroelectric And Piezoelectric Properties

Approximately 25 μm Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) thick film was synthesized based on a sol-gel/composite route. The obtained PMN-PT thick film was successfully transferred from the Silicon substrate to the conductive silver epoxy using a novel wet chemical method. The mechanism of this damage free transfer was explored and analyzed. Compared with the film on Silicon substrate, the transferred one exhibited superior dielectric, ferroelectric and piezoelectric properties. These promising results indicate that transferred PMN-PT thick film possesses the capability for piezoelectric device application, especially for ultrasound transducer fabrication. Most importantly, this chemical route opens a new path for transfer of thick film.

Structural Characteristics and Piezoelectric Properties of Electrospun Piezoelectric nanofibers

2005 ◽  
Vol 888 ◽  
Author(s):  
Yong Shi ◽  
Shiyou Xu ◽  
Sang-Gook Kim ◽  
Matthew Libera
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Electrospinning Process ◽  
Hysteresis Curve ◽  
Micro Fabrication ◽  
Pure Perovskite Phase ◽  
Promising Application

ABSTRACTThis paper reports the development and characterization of PZT nanofibers with average diameters ranged from 50 to 150 nm for various sensing and actuation applications. PZT nano fibers have been developed by sol-gel electrospinning process. Both randomly distributed and uniaxially aligned PZT fibers were obtained from the sol-gel solution with viscosity modified by polyvinyl pyrrolidone (PVP). The diameters of the nano fibers can be further reduced or controlled for different applications. The morphology and structure of the nanofibers were examined with SEM, TEM and XRD. We used two-step process to anneal the electrospun fibers and XRD confirmed that pure perovskite phase was formed after the as-spun fibers being annealed at about 650°C. TEM results showed that the grain size of the fibers was about 10 nm. Microelectromechanical (MEMS) based micro-fabrication technologies were used to assist the development of the nano-fibers in designing the test samples, depositing and patterning the electrodes, and also testing the performance of the nano fibers. Different approaches have been explored to fabricate the uniaxially aligned nano fibers. SEM results showed that partial aligned PZT nano-fibers were obtained on the pre-patterned substrats. Interdigitated Electrodes were evaporated on the partial aligned fibers by using shadow mask. Hysteresis curve of the nano piezoelectric fibers was also obtained, however further tests are still needed to get accurate measurement. The obtained PZT nanofibers have promising application potentials in designing and enabling micro and nano devices.

scholarly journals Controlled Synthesis and Microstructural Properties of Sol-Gel TiO2 Nanoparticles for Photocatalytic Cement Composites

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 26 ◽  
Author(s):  
Elena Cerro-Prada ◽  
Sara García-Salgado ◽  
M.Angeles Quijano ◽  
Fernando Varela
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Tio2 Nanoparticles ◽  
Anatase Phase ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Titania Nanoparticles ◽  
Structural Defects ◽  
Microstructural Properties ◽  
Anatase Nanoparticles

Titania nanoparticles are intensely studied for photodegradation applications. Control of nanoscale morphology and microstructural properties of these materials is critical for photocatalytic performance. Uniform anatase-type TiO2 nanoparticles were prepared by the sol-gel process using titanium isopropoxide as precursor. Controlled annealing up to 400 ℃ established crystallization and particle size ranging between 20 and 30 nm. Detailed thermal examination reveals that anatase phase transformation into rutile is affected by the annealing temperature and by the initial particle size. The anatase to rutile phase transformation occurs in the nanoparticles at 550 ℃. The Total Reflection X-ray Fluorescence (TXRF) study of the anatase nanoparticles shows a shift towards higher energy in the Ka Ti line of 10 eV, related to structural defects. These features were discussed in the photocatalytic behavior of several cement-based materials modified with the so-prepared anatase nanoparticles. The photocatalytic activity of the anatase-type TiO2/cement mortar system is evaluated from the degradation of Methylene Blue (MB) under UV irradiation, monitored through the absorbance at 665 nm. The results show that the photocatalytic composites exhibit up to 76.6% degradation efficiency. Mechanical testing of the nano-TiO2 modified cementitious composites evinces a moderate reinforcement of the strength properties at long ages.

Effect of the Fuel Type on the Synthesis of Barium Strontium Titanate by Sol-Gel Combustion Method

2013 ◽  
Vol 802 ◽  
pp. 149-153
Author(s):  
Chanyaphak Thongchanthep ◽  
Sarawut Thountom
Keyword(s):  
Acid Treatment ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Ferroelectric Ceramic ◽  
Molar Ratio ◽  
Tem Analysis ◽  
Barium Strontium ◽  
Gel Combustion ◽  
Gel Combustion Method

The ferroelectric ceramic, Barium Strontium Tinanate (Ba0.7Sr0.3TiO3), was prepared by the sol-gel combustion method using citric acid, urea, and glycine as the fuel for reduce the calcination temperature. The molar ratio of sol powderto fuel was 1:1. All of the samples were calcined at 450, 550, 650, 750, 850 and 950°C for 2 h. Then,Ba0.7Sr0.3TiO3powders were applied with acid treatment process. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) analysis were used to characterize the crystal structure and microstructure. The perovskite phases of BST and the pyrochlore (BaCO3,SrCO3) were obtained after the calcinations temperature of 550°C. BST powders were applied with acid treatment process.The XRD result showed the pure perovskite phase without the phase of pyrochlore in all of the samples. Ba0.7Sr0.3TiO3was in cubic structure, corresponding to JCPDS 34-0411. SEM analysis of BST powders calcined at 750°C.The particles were spherical morphology and had agglomerates while the particles sizes were larger corresponding with the increase of calcinations temperature.The results for TEM analysis of the BST powders prepared by using urea as the fuel had a smaller particles,and the average of particle size was about 47 nm.

Dielectric Performance of (1-x)Na0.5Bi0.5TiO3-xBaTiO3 Lead-Free Piezoelectric Ceramics Synthesized by Sol-Gel Combustion Method

2014 ◽  
Vol 809-810 ◽  
pp. 764-769
Author(s):  
Miao Yao ◽  
Hui Ling Du ◽  
Xian Du ◽  
Jun Liu ◽  
Li Xia Long
Keyword(s):  
High Temperature ◽  
Piezoelectric Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Peak Shift ◽  
Lead Free ◽  
Temperature Spectrum ◽  
Gel Combustion ◽  
Anomalous Peak ◽  
Gel Combustion Method

Lead-free piezoelectric ceramics (1-x)Na0.5Bi0.5TiO3-xBaTiO3(x=0.04, 0.06, 0.08) was synthesized via sol–gel combustion method. Structural analysis was performed by using X-ray diffraction (XRD). The structural morphology of the nanoparticles was studied using scanning electron microscopy (SEM). The ceramics show a rhombohedral-tetragonal morphotropic phase boundary (MPB) in the range of x =0.04-0.08, which makes ceramics having superior dielectric and piezoelectric properties. There is a decrease of the grain size with increasing BT concentration, suggesting that dissolving BT into NBT inhibits the grain growth. And the multi-peak fitting result shows lattice constants of NBT have increased with the BT doped into NBT. Belong to the ionic polarization relaxation type, the low temperature dielectric anomalous peak shift towards a high temperature and the high temperature dielectric anomalous peak shift towards a lower temperature showed by the dielectric-temperature spectrum. Dielectric-temperature spectrum further determines that (1-x)NBT-xBT ceramics are relaxation ferroelectrics, and join BT makes the Curie temperature decreasing about 21 to 24°C. High piezoelectric properties with d33=148pC/N are observed in NBT-BT0.06.

Phase-formation kinetics of xerogel and electrical properties of sol-gel-derived BaxSr1−xTiO3 thin films

1997 ◽  
Vol 12 (5) ◽  
pp. 1327-1334 ◽  
Author(s):  
Soo-Ik Jang ◽  
Byung-Cheul Choi ◽  
Hyun M. Jang
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Life Time ◽  
Titanium Isopropoxide ◽  
Hydrolysis Rate ◽  
Relative Dielectric Permittivity ◽  
Strontium Chloride ◽  
Heating Rates ◽  
Enolic Form

Chemically homogeneous BaxSr1−xTiO3 (BST with x = 0.6) multicomponent sol was synthesized using barium oxide, strontium chloride, and Ti-alkoxide (titanium isopropoxide) as starting materials. Acetylacetone (AcAc) was introduced as a chelating agent to reduce a rapid hydrolysis rate of Ti-alkoxide. Analysis of Fourier transform infrared spectroscopy (FTIR) spectra indicated that the stabilization of BST sols was achieved by the chelation of Ti-alkoxide with the enolic form of AcAc. The effective activation energy associated with the formation of perovskite phase from the xerogel was estimated by the differential thermal analysis (DTA) experiment using various heating rates. It is approximately 400 kJ/mol with the Avrami exponent (reaction order) of n = 1, suggesting that the growth of perovskite BST is diffusion-controlled. The calculated half-life time suggests that the minimum temperature for the crystallization which is practically accessible to a real processing is approximately 600 °C. The BST thin film fabricated on the “Pt(150 nm)/Ti(100 nm)/SiO2(100 nm)/Si” substrate exhibited the relative dielectric permittivity of 310 and can be represented by an equivalent circuit consisting of a resistive component originated from the bulk perovskite grain and a parallel RC component resulting from the presence of the grain boundary.

Piezoelectric Properties Study of KNN-LS Lead-Free Ceramics Synthesized by Sol-Gel Method

2014 ◽  
Vol 538 ◽  
pp. 15-18 ◽  
Author(s):  
Xin Jin ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Yang Lu Hou
Keyword(s):  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Second Phase ◽  
Gel Method ◽  
Sol Gel Method ◽  
Fine Grained ◽  
Lead Free Ceramics

Morphotropic phase boundary (MPB) composition, KNaNbO3-0.052LiSbO3(KNN-LS) was synthesized by sol-gel method at this experiment. Sb2O3 was used as economic Sb source and the final dried gel was calcined at 650°C for 2h to obtain white nanopowder. The sintering experiment was carried out at the temperature range of 980°C-1130°C, and perovskite phase structure could be observed apparently below 1080°C. When the temperature reached 1080°C and above, the second phase Na3LiNb6O17 appeared meanwhile the piezoelectric coefficient (d33) decreased quickly. Its proven that fine-grained particles and low sintering temperature could be obtained in sol-gel route.

Sol-Gel Processing and Novel Physical Properties of PLZT 7/57/43 Ferroelectric Ceramics

2013 ◽  
Vol 873 ◽  
pp. 292-297 ◽  
Author(s):  
Ke Yu Zheng ◽  
Ya Li Ding ◽  
Ren Zhi Shao
Keyword(s):  
Physical Properties ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Ferroelectric Ceramics ◽  
Nominal Composition ◽  
Electrical Measurements ◽  
Sol Gel Process ◽  
Dta Studies

The sol-gel process was employed to prepare (Pb1-xLax)(Zr1-yTiy)O3(PLZT) ceramics with nominal composition Pb0.93La0.07(Zr0.57Ti0.43)0.9825O3. The structure and physical properties such as dielectric, piezoelectric and ferroelectric properties were investigated. X-ray diffraction results showed that the perovskite phase PLZT was formed when the sol-gel processed powders was calcined at 600°Cfor 4 hours. nanocrystalline particles with a size of ~50nm were found. TG-DTA studies were used to analyze the thermal properties of nanopowders for understanding the reaction kinetics in them. Wafered bulk ceramic samples prepared from the sol-gel derived powders were subjected to electrical measurements, in order to determine the dielectric, piezoelectric and ferroelectric properties. The dielectric properties of the PLZTBST system are further improved and the dielectric piezoelectric properties of PLZT ceramics are found to be sensitive to the particle size of PLZT nanopowders. The dielectric piezoelectric properties of polarized PLZT ceramics can be improved with the lessening of PLZT nanopowder size. Meanwhile, the grain size of PLZT ceramics decreases.

The Effects of the Precursor Solutions on the Structure and the Properties of Sol-Gel Derived Bst Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
Jeong Seon Ryoo ◽  
Seong Jun Kang ◽  
Yung Sup Yoon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Barium Strontium Titanate ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Barium Acetate ◽  
Bst Thin Films ◽  
Barium Strontium ◽  
Bst Thin Film ◽  
Strontium Acetate

AbstractWe have studied the effects of solvents and additives in the precursor solutions on the characteristics of barium strontium titanate (BST) thin films. The solution having two solvents, ie. acetic acid for barium acetate and strontium acetate and 2-methoxyethanol for titanium isopropoxide and also having an additive of ethylene glycol shows good stability and remains homogeneous even after a month of ageing. It produces excellent BST thin film without cracks. Dielectric constant, loss tangent at 10kHz and leakage current density at 3V of the BST(70/30) thin film made from this solution are 339, 0.052 and 13.3μA/cm2, respectively. We have also found that a Ta layer is a better diffusion barrier against Si than a Ti layer and is functional up to 750°C.

scholarly journals Synthesis and characterization of nanocrystalline barium strontium titanate powder by a modified sol-gel processing

2016 ◽  
Vol 34 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M.E. Azim Araghi ◽  
N. Shaban ◽  
M. Bahar
Keyword(s):  
Sol Gel ◽  
Research Work ◽  
Titanium Isopropoxide ◽  
Barium Acetate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Crystallite Sizes ◽  
Ft Ir ◽  
Strontium Acetate

AbstractIn this research work, nanocrystalline BST (Ba0.6Sr0.4TiO3) powders were synthesized through a modified sol-gel process, using barium acetate, strontium acetate and titanium isopropoxide as the precursors. In this process, stoichiometric proportions of barium acetate and strontium acetate were dissolved in acetic acid and titanium (IV) isopropoxide was added to form BST gel. The as-formed gel was dried at 200 °C and then calcined in the temperature range of 600 to 850 °C for crystallization. The samples were characterized by infrared spectroscopy method (FT-IR), X-ray diffraction technique (XRD) and field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy. EDS analysis of these samples confirmed the formation of the final phase with the special stoichiometry. The formation of a cubic perovskite crystalline phase with nanoscale dimension was detected using the mentioned techniques. The results showed that the obtained crystallite sizes were 33 and 37 nm for BST powder calcined at 750 and 850 °C, respectively.

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