Preparation and Ferroelectric Properties of Sol-Gel Derived (Ba0.95Ca0.05)TiO3 Ceramics

2011 ◽  
Vol 418-420 ◽  
pp. 362-367
Author(s):  
Xue Liang Yang ◽  
Xiang Yun Deng ◽  
Li Ren Han ◽  
Ren Bo Yang ◽  
Yan Jie Zhang ◽  
...  
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Structural Evolution ◽  
Ferroelectric Ceramics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Maximum Dielectric Constant ◽  
Sol Gel Process

Ba0.95Ca0.05)TiO3 (BCT) ferroelectric ceramics were prepared from powders synthesized using a sol–gel process. Structural evolution of the BCT dry gels are investigated by thermal gravimetric analysis differential scanning calorimetry. It is found that BCT crystallites can be formed before 800°C. Well-sintered samples are synthesized at 1320°C for 2h. The crystal structure of the BCT ceramics is studied by XRD and ferroelectric properties of the ceramics are characterized by TF analyzer 2000. The Curie temperature Tc of the BCT ceramics is at about 130°C. The maximum dielectric constant (εr) reaches about 13678 at 130°C and hysteresis loops are measured with the temperature range from 25°C to 150°C.

Preparation and Ferroelectric Properties of (Ba0.7Ca0.3)TiO3 Ceramics

2010 ◽  
Vol 148-149 ◽  
pp. 1016-1020
Author(s):  
Li Ren Han ◽  
Wei Guo Fu ◽  
Xiang Yun Deng ◽  
Xiao Fen Guan ◽  
Zhong Wen Tan ◽  
...  
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Structural Evolution ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Maximum Dielectric Constant ◽  
Gel Technique ◽  
Curie Temperature Tc

(Ba0.7Ca0.3)TiO3 (BCT) powders and ceramics have been prepared by sol-gel technique. Structural evolution of the BCT dry gels are investigated by thermal gravimetric analysis–differential scanning calorimetry. It is found that BCT crystallites can be formed before 800 . Well-sintered samples are synthesized at 1260 for 2h. The crystal structure of the BCT powders is studied by XRD and ferroelectric properties of the ceramics are characterized by TF analyzer 2000. The Curie temperature Tc of the BCT ceramics is at about 125 . The maximum dielectric constant (εr) reaches about 4851 at 125 and hysteresis loops are measured with the temperature range from 25 to 150 .

Fabrication of Iron Carbide and Nitride Ceramics with Controlled Magnetic Properties by the Non-Oxide Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 1429-1433
Author(s):  
Xun Lao ◽  
Xiao Yan ◽  
Jiao Xie ◽  
Ya Li Li
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Iron Carbide ◽  
Iron Nitride ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Ferromagnetic Properties ◽  
Sol Gel Process ◽  
Nitride Ceramics ◽  
Carbide Ceramics

The carbodiimide-based non-oxide sol-gel process is a novel route to non-oxide nitride and carbide ceramics. This process has been applied to fabricate ternary or binary silicon based nitride and carbide ceramics. Based on this non-oxide sol-gel process, iron carbide and nitride have been fabricated by reaction of iron trichloride with bis(trimethylsilyl)carbodiimide to form FeCN gel followed by pyrolysis in argon flow at different temperatures. The iron carbide material obtained at 700 °C exhibits hard ferromagnetic properties whereas α-iron along with iron nitride formed at 1300 °C shows soft ferromagnetic properties. Therefore, iron carbide and nitride ceramics with controlled magnetic properties can be obtained along this novel non-oxygen sol-gel process by controlled pyrolysis. The pyrolysis behavior was investigated based on thermal gravimetric analysis coupled with differential scanning calorimetry. The phase structures of the iron carbide and nitride are identified by X-ray diffraction and the magnetic properties of the materials are measured by magnetometer.

Study of Pseudoboehmite Synthesis by Sol-Gel Process

2006 ◽  
Vol 45 ◽  
pp. 260-265 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
G.N. Uehara
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

Effect of Sintering Temperature on Structure and Electric Properties of (Ba0.96Ca0.04)(Zr0.05Ti0.95)O3 Ceramics

2015 ◽  
Vol 655 ◽  
pp. 141-146
Author(s):  
Xin Guan ◽  
Xiang Yun Deng ◽  
Jian Hao ◽  
Guang Hao Sun ◽  
Chuang Jun Huang
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Calcium Titanate ◽  
Ferroelectric Ceramics ◽  
X Ray Diffraction ◽  
Pure Perovskite Structure ◽  
Maximum Dielectric Constant ◽  
Gel Technique

Barium calcium titanate (Ba0.96Ca0.04)(Zr0.05Ti0.95)O3 ferroelectric ceramics were prepared by sol–gel technique. The ceramics were sintering at 1290°C-1370°C. X-ray diffraction was employed to investigate the microstructure, and the surface topography was investigated by SEM graphs. The dielectric constant vs temperature was measured by Temperature dielectric spectrometer, and TF Analyzer 2000 measured the ferroelectric properties. It can be found that all the ceramics show pure perovskite structure suggesting that solid solution were formed. SEM showed that the samples uniform in grain size at 1330 °C. Our study revealed that when the sintering temperature is 1330 °C the maximum dielectric constant was 29,600, the maximum piezoelectric coefficient d33 could reach 399pm/V and the remanent polarization (Pr) was 8.3 μc/cm2, respectively.

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.

Nano Composite Membranes of Sulfonated Amine-Poly(ether sulfone)s and SiO2 for Fuel Cell Application

2010 ◽  
Vol 658 ◽  
pp. 392-395 ◽  
Author(s):  
Dong Wan Seo ◽  
Young Don Lim ◽  
Soon Ho Lee ◽  
Md. Monirul Islam ◽  
Hyun Mi Jin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Nano Composite ◽  
Fuel Cell Application ◽  
Sol Gel Process ◽  
20 Nm

Organic-inorganic Nano composite membranes were prepared by Sulfonated amine-poly(ether sulfone)s (S-APES)s and SiO2. S-APESs were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason®-S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(Ⅱ)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH2-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. Organic-inorganic nano composite membranes were obtained by mixing S-APES (45 %) with hydrophilic SiO2 (20 nm, 4-10 %) obtained by sol-gel process. Different contents of SiO2 of the S-APES were studied by FT-IR, 1H-NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The nano composite membranes exhibit conductivities (25 °C) from 3.51 x 10-3 to 4.10 x 10-3 S/cm, water swell from 57.25 to 60.50 %, IEC from 0.68 to 0.73 meq/g, and methanol diffusion coefficients from 2.81 x 10-7 to 3.33 x 10-7 cm2/S at 25 °C.

Inducing Layer Dependence of BiFeO3 Based Multilayer Capacitors

2009 ◽  
Vol 60-61 ◽  
pp. 256-259 ◽  
Author(s):  
Ya Feng Luo ◽  
Dan Xie ◽  
Yong Yuan Zang ◽  
Rui Song ◽  
Tian Ling Ren ◽  
...  
Keyword(s):  
Thin Films ◽  
Applied Voltage ◽  
Room Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Sol Gel Process ◽  
Capacitance Voltage ◽  
Voltage Hysteresis ◽  
Multilayer Capacitors

Multifunctional BiFeO3 (BFO) thin films were deposited on Bi3.15Nd0.85Ti3O12 (BNdT)/Pt and Pb(Zr1−x,Tix)O3 (PZT)/Pt substrates respectively by sol-gel process. The ferroelectric properties were studied for Metal-Ferroelectric-Mental (MFM) capacitors. The MFM structure exhibited well clockwise capacitance-voltage hysteresis loops due to the ferroelectric polarization of multilayer thin films achieved. The remnant polarization (2Pr) of the BFO/PZT and BFO/PZT multilayer capacitors were 45.1μC/cm2 and 23.2μC/cm2, respectively at the applied voltage of 8V. The leakage current of Pt/BFO/BNdT/Pt is about 3×10-5A/㎝2 at applied voltage of 4V, one order smaller than Pt/BFO/PZT/Pt capacitor. For the BFO/BNdT/Pt, it exhibited a weak saturated ferromagnetic response at room temperature and the multilayer was anti-ferromagnetic. However, for the BFO/PZT/Pt, well-developed M-H loops together with remnant magnetizations can be observed in at room temperature. The highest saturation magnetizations (Ms) of both capacitors were measured to be 2.47emu/cm3.

Film Thickness-Dependent Microstructures and Dielectric Properties of Pb(Zr,Ti)O3 Thick Films by Sol-Gel Processing

2011 ◽  
Vol 80-81 ◽  
pp. 688-692 ◽  
Author(s):  
Ya Ting Zhang ◽  
Xiu Jian Chou ◽  
Wen Ping Geng ◽  
Ying Tian ◽  
Ji Jun Xiong ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Film Thickness ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Thick Films ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Lead Zirconate ◽  
Sol Gel Process ◽  
Gel Processing

Lead zirconate titanate thick films with thickness of 1-3μm have been prepared by a sol-gel process. Influence of film thickness on microstructures and dielectric properties of the films were investigated. The film thickness dependent of microstructures was studied by XRD and Raman spectrum. The PZT films were dense and possessed preferential crystal orientation. Ferroelectricity and dielectric properties were confirmed by P–E hysteresis loops and C-E measurements. The dielectric constant and dielectric loss of the film with thickness of 3.045μm were 2000 and 0.055, respectively. The decrease of the coercive field and the increase of the remanent polarization with the increase in thickness were observed. As film thickness was increasing, PZT thick films had higher (110)-preferred growth orientation and excellent dielectric and ferroelectric properties.

Synthesis and Ferroelectric Properties of Sol–Gel Derived Intergrowth-Superlattice-Structured SrBi4Ti4O15-Bi4Ti3O12 Thin Films

2011 ◽  
Vol 197-198 ◽  
pp. 1781-1784
Author(s):  
Hua Wang ◽  
Jian Li ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Annealing Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Si Substrates ◽  
Gel Processing ◽  
Coercive Electric Field ◽  
Clockwise Hysteresis

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.

Synthesis, Characterization and Application of Multi-Generations Hyperbranched Polyurethane Based on Isophorone Diisocyanate

2012 ◽  
Vol 554-556 ◽  
pp. 126-129 ◽  
Author(s):  
Shun Yin ◽  
Ning Sun ◽  
Chun Yun Feng ◽  
Zhi Mou Wu ◽  
Zhao Hua Xu ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raw Materials ◽  
Degradation Mechanism ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Isophorone Diisocyanate ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Hyperbranched Polyurethane

A series of different generation hyperbranched polyurethane(HBPU) was synthesized based on the raw materials of isophorone diisocyanate(IPDI) and diethanolamine(DEOA). Their structure, thermal degradation mechanism and glass transition temperature(Tg) were characterized by fourier transform infrared spectroscopy(FTIR), nuclear magnetic resonance spectroscopy(NMR), thermal gravimetric analysis(TGA) and differential scanning calorimetry(DSC). The results showed that: the yield of each generation HBPU was up to 90%, different generation HBPU had almost the same initial degradation temperature(about at 200°C) and they all had two decomposition platforms; with the increase of generation, Tg increased from 107.2°C to 132.1°C. The gloss and hardness of the HBPU coatings were significantly improved.

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