Mechanochemical Synthesis and Characteristics of Pb(Mg1/3Nb2/3)O3

2010 ◽  
Vol 177 ◽  
pp. 29-31
Author(s):  
Hao Wu ◽  
Cheng Chen ◽  
Dan Yu Jiang ◽  
Tao Feng ◽  
Qiang Li
Keyword(s):  
Mechanochemical Synthesis ◽  
Milling Time ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
Ferroelectric Material ◽  
Nano Particles ◽  
Processing Route ◽  
Sem Images ◽  
Lower Temperature ◽  
Xrd Patterns

This paper presents a novel mechanochemical synthesis technique for making nano-structured Pb(Mg1/3Nb2/3)O3 (PMN) ferroelectric material without annealing treatment in a much shorter time and at much lower temperature than those reported in the literature, by using the starting precursors MgO, PbO, and Nb2O5. Specimens of various milling time (3-6h) are characterized from XRD patterns to track and analyze the synthesizing procedure of this mechanochemical processing route. The time used to make the desired PMN powders varies with different milling power. When the constituent oxides were mechanically activated at 1.8KW milling power for 6h, the perovskite phase PMN powder was obtained; while it was formed when milling at 3KW for only 3h. Typical SEM images of the as-received PMN powders show that the powders are aggregated of nano-particles of about 100nm in size.

scholarly journals Electrochemical Properties of Ce0.5Sr0.5 (Co0.8Fe0.2)1−xZrxO3−δ Cathode Materials for Low Intermediate Temperature Solid Oxide Fuel Cells (LIT-SOFCs) Synthesized by Sol-Gel Method

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Beyene Tesfaw Ayalew ◽  
P. Vijay Bhaskar Rao
Keyword(s):  
Electrochemical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Partial Substitution ◽  
Sem Images ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystallite Sizes ◽  
Xrd Patterns

Ce0.5Sr0.5 (Co0.8Fe0.2)1−x ZrxO3−δ (CSCFZ) powders were synthesized by the sol-gel method and characterized to study structural and electrochemical properties. X-ray diffractometer (XRD) patterns of all samples give nanosized particles of a high-degree crystalline cathode having a cubic-type perovskite structure of space group Pm-3m with the existence of oxygen vacancies in the lattices. The results have the perovskite phase with average crystallite sizes of 26.57 nm, 18.14 nm, 18.13 nm, and 18.12 nm with porosities of 9.93%, 9.87%, 9.50%, and 9.08% for x = 0, 0.1, 0.15, and 0.2, respectively. Scanning electron microscope (SEM) micrographs showed the presence of pores on the microstructure. Average grain sizes of prepared samples found from SEM images were in the range of 105.30–183.02 nm. The partial substitution of zirconium at the B-site shows more stable materials than the host without decreasing the porosity that much. The results of electronic conductivity analyzed by the four-probe dc technique show that the conductivity of synthesized materials increases with the increment of both dopant concentration and temperature by the decrement of area specific resistances. The electrical conductivity of CSCFZ steadily increased with the increment of temperature which reached 42.76 Scm−1 at around 450°C.

Effects of Annealing on Ferroelectric, Optical and Electrically Controlled Light Scattering Properties of PLZT Transparent Ceramics

2017 ◽  
Vol 898 ◽  
pp. 1686-1692
Author(s):  
Lei Tao Nie ◽  
Xi Yun He ◽  
Xia Zeng ◽  
Ping Sun Qiu ◽  
Wen Xiu Cheng ◽  
...  
Keyword(s):  
Light Scattering ◽  
Electric Field ◽  
Perovskite Phase ◽  
Contrast Ratio ◽  
Annealing Treatment ◽  
Second Phase ◽  
Transparent Ceramics ◽  
Field Range ◽  
Xrd Patterns ◽  
Ferroelectric Hysteresis

PLZT (X/70/30) ceramics with different La contents (X=7.45, 7.54, 7.63 mole%) were fabricated by hot-press sintering techniques. The effects of annealing on ferroelectric, optical and electrically controlled light scattering properties of PLZT transparent ceramics were examined and analyzed. The XRD patterns indicated that all the samples were crystallized into a pure perovskite phase without the second phase. The SEM exhibited fully dense, uniform microstructures with well-developed grains. The annealing treatment weakened the degree of squareness of the ferroelectric hysteresis loop, and even the anti-ferroelectric phase occurred as the La content increasing to X=7.63. The remnant polarization (Pr) and coercive electric field (Ec) decreased with the annealing treatment for all samples. The slow annealing treatment resulted in the lager increase of both transmittance and contrast ratio than those of the rapid annealing treatment at λ=632.8nm. The electrically controlled light scattering properties were obviously enhanced by the annealing treatment. Especially, the PLZT (7.63/70/30) ceramics exhibited the different electrically controlled light scattering performance which indicated it could hold high transmittance and symmetry in a wide electric field range with the slow annealing treatment.

Synthesis and Electrical Properties of La Doped SrTiO3 Powders by Ultrasonic Spray Pyrolysis

2013 ◽  
Vol 582 ◽  
pp. 115-118 ◽  
Author(s):  
Ken Genji ◽  
Kenichi Myoujin ◽  
Takayuki Kodera ◽  
Takashi Ogihara
Keyword(s):  
Spray Pyrolysis ◽  
Perovskite Phase ◽  
Ultrasonic Spray Pyrolysis ◽  
Metal Nitrate ◽  
Open Circuit ◽  
Sem Images ◽  
Reducing Atmosphere ◽  
Ultrasonic Spray ◽  
Xrd Patterns ◽  
La Doped

La-doped SrTiO3 (LST) powders were synthesized by ultrasonic spray pyrolysis using an aqueous solution of a metal nitrate. SEM images showed that the as-prepared LST powders had a spherical morphology with a diameter of 1 μm. XRD patterns showed that the crystal phase of the as-prepared powders was amorphous and that the powders crystallized to the perovskite phase by calcination at 900 °C. The sintered LST body had the highest electrical conductivity at a La doping concentration (Lax) of 0.1 under a reducing atmosphere. A solid oxide fuel cell (SOFC) with La0.1Sr0.9TiO3Sm-doped CeO2 (1:9) as the anode exhibited a maximum power density of 137.8 mW/cm2 and an open circuit voltage of 1.08 V at 880 °C.

Structure and CO Gas Sensing Properties of PPy/LaFeO3 Nanocomposites

2011 ◽  
Vol 675-677 ◽  
pp. 375-378
Author(s):  
Peng Song ◽  
Qi Wang
Keyword(s):  
Gas Sensing ◽  
Perovskite Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Lafeo3 Nanoparticles ◽  
Xrd Patterns ◽  
Polymerization Method ◽  
Co Gas

In this paper, perovskite LaFeO3 nanoparticles were synthesised by a sol-gel method. Then, polypyrrole (PPy)/LaFeO3 nanocomposites were prepared by a simple in situ chemical polymerization method. By means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), the microstructure of PPy/LaFeO3 nanocomposites was characterized. The XRD patterns indicated that LaFeO3 nanoparticles have a perovskite phase with orthorhombic structure, and incorporation of PPy did not change the crystalline structure of LaFeO3. The PPy was evenly dispersed on the surface of LaFeO3 particles, which was endorsed by FTIR spectral analyses. And SEM images indicate that the PPy was evenly dispersed on the surface of LaFeO3 particles without apparent agglomeration. And we found that the nanocomposites exhibited a higher response to CO gas.

scholarly journals Effect of Gd doping on Structural, Morphological and Magnetic Properties of Mn-Zn Soft Ferrites Nanoparticles

2021 ◽  
Author(s):  
Anjali Shrivastava ◽  
Ashwani Kumar Shrivastava
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Morphological Characteristics ◽  
Lattice Parameter ◽  
Nano Particles ◽  
Sem Images ◽  
Manganese Zinc ◽  
Manganese Zinc Ferrite ◽  
Xrd Patterns ◽  
Co Precipitation

Abstract Co-precipitation technique was adopted to synthesize gadolinium doped manganese-zinc ferrite nano particles with varying concentration 0, 0.1, 0.2 and 0.3. XRD patterns authenticated the ferrite innovate in the as-prepared samples. The lattice parameter, crystallite size, lattice strain and x-ray density has been calculated. The crystallite size is comes bent on be around 5 nm. The FTIR spectra reveal that every one the functional groups are present within the material. SEM images are accustomed to indicate the morphological characteristics of the as-prepared samples. Magnetic properties show the decrease in saturation magnetization from 37.57emu/g to 30.15emu/g with reference to increase in gadolinium doping from 0.1 to 0.3.

Preparation and Characterization of NTC NiMn2O4-La1-xCaxMnO3 (0≤x≤0.3) Composite Ceramics

2013 ◽  
Vol 716 ◽  
pp. 78-83 ◽  
Author(s):  
Hui Min Zhang ◽  
Fang Guan ◽  
Ai Min Chang ◽  
Li Jun Zhao
Keyword(s):  
Electrical Resistivity ◽  
Perovskite Structure ◽  
Spinel Structure ◽  
Thermal Constant ◽  
Inrush Current ◽  
Composite Ceramics ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Xrd Patterns

Composite ceramics made of spinel structure NiMn2O4 and CaO-doped perovskite structure LaMnO3 were prepared by a conventional solid state reaction and sintered at different temperatures. The XRD patterns have shown that the major phases presented in the sintered samples are NiMn2O4 compounds with the spinel structure, La1-xCaxMnO3 with the perovskite structure and NiO with a monoclinic structure. SEM images show that the density and grain size of the composite ceramics increases with sintered temperature increasing. The electrical resistivity of the composite ceramics at 25°C is found to change significantly depending on the CaO content, while the thermal constant B is still reasonably large in the range of 2400 to 3000 K. For the composition x = 0.1, the composite with a low electrical resistivity (ρ25°C=4.46Ω·cm) and moderate B value (B25/50=2762K) was obtained. These composites could be applied as potential candidates for NTC thermistors in the suppression of the inrush current.

EFFECT OF AMMONIA SOLUTION ON COMPOSITION, STRUCTURE AND MAGNETIC PROPERTIES OF CHEMICALLY PREPARED Co-B NANO-PARTICLES

2012 ◽  
Vol 05 ◽  
pp. 134-141
Author(s):  
HOOMAN SABAROU ◽  
ABOLGHASEM ATAIE
Keyword(s):  
Magnetic Properties ◽  
Boron Content ◽  
Fine Particles ◽  
Chemical Reduction ◽  
Amorphous Structure ◽  
Ammonia Solution ◽  
Nano Particles ◽  
Reagent Solution ◽  
Sem Images ◽  
Composition Structure

In this study, the effect of ammonia solution addition as a pH adjusting component on the thermal behavior, phase composition, morphology, and magnetic properties of reduced Co - B nano-particles fabricated by chemical reduction route have been studied using DSC, XRD, SEM, and VSM techniques, respectively. Chemical composition of the samples was measured by ICP. The ICP results showed that basic pH of reagent solution, derived from utilizing ammonia solution, caused the boron content to decrease. XRD results indicated an amorphous structure for both samples synthesized with and without ammonia solution. Analysis of the DSC results showed that crystallization behavior has dramatically altered, owing to utilize ammonia solution. While the sample synthesized without ammonia solution showed three distinctive exothermic peaks at 216,470, and 540°C, the sample synthesized in the presence of ammonia solution exhibited only two exothermic peaks at 235 and 470°C and one endothermic peak at 370°C. SEM images reveal that the samples have a net- like morphology and the net is formed by many interconnected spherical fine particles with sizes less than 100 nm. Saturation magnetization of the sample synthesized in the presence of ammonia solution has improved significantly, probably due to the less amount of boron.

Synthesis, Characterization and Properties of PANI/(La-Nd Doped BaFe12O19) Composites

2017 ◽  
Vol 727 ◽  
pp. 327-334
Author(s):  
Yan Wang ◽  
Jun Wang ◽  
Xiao Fei Zhang ◽  
Ya Qing Liu
Keyword(s):  
Sol Gel ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Structure Morphology ◽  
Xrd Patterns ◽  
Hexagonal Platelet ◽  
Peak Value ◽  
Properties Of Composites

La-Nd co-doped barium hexaferrites, Ba0.7(LamNdn)0.3Fe12O19 (D-BaM), were successfully prepared by sol-gel method. PANI / D-BaM composites were synthesized by in-situ polymerization in solution. The structure, morphology and properties of samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), four-probe conductivity tester and vector network analyzer. The XRD patterns showed that the crystal structure of all the samples exist as M-type phases. The SEM images revealed that the particles presented a hexagonal platelet-like morphology. The magnetic properties could be improved by substitutions of La and Nd ions. The saturation magnetization (Ms) and coercive force (Hc) increased with the change of La / Nd ratio to the maximum at La / Nd = 3:1. The doped particles have also been embedded in conductive PANI to prepare electromagnetic materials, and the conductivity kept on the order of 10-2. The microwave absorbing properties of composites at 30 MHz-6 GHz improved obviously, the peak value of reflection loss could reach-7.5 dB.

Preparation of catalyst as Au doped Mn1Co9Ox/ceramic system for total oxidation of CO

2021 ◽  
Vol 10 (4) ◽  
pp. 39-45
Author(s):  
Phuong Pham Thi Mai ◽  
Hoan Nguyen Quoc ◽  
Quan Do Quoc ◽  
Hung Nguyen Thanh
Keyword(s):  
Sol Gel ◽  
Active Phase ◽  
Catalyst System ◽  
Oxidation Of Co ◽  
Sem Images ◽  
Total Oxidation ◽  
Wet Impregnation ◽  
Modern Analysis ◽  
Catalyst Powder ◽  
Xrd Patterns

In this paper, the Au doped Mn1Co9Ox was investigated for total oxidation of CO. The sol-gel method was applied to prepare this catalyst and some modern analysis methods as XRD, EPR, TPx, SEM were utilized to characterize its properties. The XRD patterns showed only Co3O4 phase without any peaks belonging to Mn or Au. However, the presence of Au and Mn was confirmed by EPR and O2-TPD results. With the aim to further apply catalyst in reality, the Au doped Mn1Co9Ox was deposited on ceramic by sol-gel, wet impregnation. The SEM images displayed the successful coating of active phase on substrate. However, the complete catalyst system didn’t have the high activity in total CO oxidation like the catalyst powder because of large agglomerations on coatings.

scholarly journals Annealing-Induced Modifications in Physicochemical and Optoelectronic Properties of Ag-Doped Nanostructured CdS Thin Films

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Vidya S. Taur ◽  
Rajesh A. Joshi ◽  
Ramphal Sharma
Keyword(s):  
Thin Films ◽  
Annealing Treatment ◽  
Cost Effective ◽  
Peak Position ◽  
Optoelectronic Properties ◽  
Sem Images ◽  
X Ray ◽  
Optical Absorbance ◽  
Air Atmosphere ◽  
Cds Thin Films

The Ag-doped nanostructured CdS thin films are grown by simple, cost effective chemical ion exchange technique at room temperature on ITO-coated glass substrate. These as grown thin films are annealed at 100, 200, 300, and 400°C in air atmosphere for 1 hour. To study the effect of annealing on physicochemical and optoelectronic properties, these as grown and annealed thin films are characterized for structural, compositional, morphological, optical, and electrical properties. X-ray diffraction (XRD) pattern reveals polycrystalline nature of these thin films with increase in crystallite size from 6.4 to 11.2 nm, from XRD the direct identification of Ag doping in CdS thin films cannot be judged, while shift in characteristics peak position of CdS is observed. The Raman spectrum represents increase in full width at half maxima and intensity of characteristic peak, confirming the material modification upon annealing treatment. Presence of Cd, Ag, and S in energy dispersive X-ray analysis spectra (EDAX) confirms expected elemental composition in thin films. Scanning electron microscopy (SEM) images represent grain growth and agglomeration upon annealing. Red shift in optical absorbance strength and energy band gap values from 2.28 to 2.14 eV is obtained.I-Vresponse obtained from as grown and annealed thin films shows an enhancement in photosensitivity from 72% to 96% upon illumination to 100 mW/cm2light source.

Sign in / Sign up

Export Citation Format

Share Document