Composition, Structure and Properties of PZT-BT Ceramics Prepared by Two-Stage Sintering

2009 ◽  
Vol 421-422 ◽  
pp. 436-439 ◽  
Author(s):  
Wanwilai C. Vittayakorn ◽  
Rattikorn Yimnirun ◽  
Supon Ananta
Keyword(s):  
Perovskite Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Two Stage ◽  
Fine Grain ◽  
Pure Perovskite Phase ◽  
One Step ◽  
Composition Structure ◽  
The One ◽  
System 1

Ceramic solid solutions within the system (1-x)PZT-xBT, where x = 0.1, 0.2, 0.3, 0.4 and 0.5, were prepared by conventional mixed-oxide method combined with a two-stage sintering procedure. A sintering time of 2 h at 1000 °C followed by a second step in the temperature range of 1000-1200 °C for 2 h was employed to all samples and compared to the one-step sintering process. Phase formation, densification and microstructure of all ceramics were examined via X-ray diffraction (XRD), Archimedes method and scanning electron microscope (SEM). The results lead to the conclusion that the pure perovskite phase and high densification of (1-x)PZT-xBT ceramics with fine grain can be successfully achieved under suitable two-stage sintering conditions.

Synthesis of Modified K0.5Na0.5NbO3 Powder by Molten-Salt Technique

2017 ◽  
Vol 728 ◽  
pp. 160-165
Author(s):  
Thanatep Phatungthane ◽  
Buagun Samran ◽  
Gobwute Rujijanagul
Keyword(s):  
Molten Salt ◽  
Calcination Temperature ◽  
Perovskite Phase ◽  
Orthorhombic Symmetry ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Fine Grain ◽  
Pure Perovskite Phase

In the present work, the molten-salt method was applied to synthesize 0.948K0.5Na0.5NbO3–0.052LiSbO3 powder for the first time. Characteristics of the powder were investigated. Based on X-ray diffraction technique, pure perovskite phase was observed at a calcination temperature of 700 oC which is lower than that required by the conventional solid-state reaction technique for ∼200 oC. Raman spectroscopy technique showed that the powder had an orthorhombic symmetry which consistent with the X-ray diffraction results. The powder exhibited very fine grain with narrow size distribution. Particle size of the obtained powders increased with increasing calcination temperature. Therefore, the molten-salt method is a simple and effective method to synthesize 0.948K0.5Na0.5NbO3 – 0.052LiSbO3 powder.

Effect of Sintering Temperature on Electrical Properties of SFN Ceramics Doped with Al Prepared by a Solid-State Reaction Technique

2016 ◽  
Vol 675-676 ◽  
pp. 527-530
Author(s):  
Thanatep Phatungthane ◽  
Kachaporn Sanjoom ◽  
Denis Russell Sweatman ◽  
Buagun Samran ◽  
Chamnan Randorn ◽  
...  
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Dielectric Behavior ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Pure Perovskite Phase

In the present work, strontium iron niobate SrFe0.5Nb0.5O3 ceramics doped with aluminum were synthesized by a solid-state reaction technique. Phase formation investigation by X-ray diffraction technique (XRD) revealed that all ceramics exhibited pure perovskite phase with orthorhombic symmetry. Grain size observed by electron microscopy (SEM) was found to increase with increasing sintering temperature. The electrical properties and related parameters of the ceramics were also measured. The ceramics exhibit very good dielectric behavior and have a significant potential for dielectric applications.

scholarly journals Sustaible Ethanol Production From Sugarcane Molasses by Saccharomyce scerevisiae Immobilized on Chitosan-Coated Manganese Ferrite

2021 ◽  
Vol 5 ◽  
Author(s):  
Arianna Núñez Caraballo ◽  
Anna Iliná ◽  
Rodolfo Ramos González ◽  
Cristóbal N. Aguilar ◽  
Georgina Michelena Álvarez ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Yeast Cells ◽  
Manganese Ferrite ◽  
X Ray Diffraction ◽  
Sugar Consumption ◽  
Total Consumption ◽  
Fermentation Time ◽  
Open Questions ◽  
One Step ◽  
The One

The interaction between nanostructures and yeast cells, as well as the description of the effect of nanoparticles in ethanol production are open questions in the development of this nanobiotechnological process. The objective of the present study was to evaluate the ethanol production by Saccharomyces cerevisiae in the free and immobilized state on chitosan-coated manganese ferrite, using cane molasses as a carbon source. To obtain the chitosan-coated manganese ferrite, the one-step coprecipitation method was used. The nanoparticles were characterized by X-ray diffraction obtaining the typical diffraction pattern. The crystal size was calculated by the Scherrer equation as 15.2 nm. The kinetics of sugar consumption and ethanol production were evaluated by HPLC. With the immobilized system, it was possible to obtain an ethanol concentration of 56.15 g/L, as well as the total sugar consumption at 24 h of fermentation. Productivity and yield in this case were 2.3 ± 0.2 g/(L * h) and 0.28 ± 0.03, respectively. However, at the same time in the fermentation with free yeast, 39.1 g/L were obtained. The total consumption of fermentable sugar was observed only after 42 h, reaching an ethanol titer of 50.7 ± 3.1, productivity and yield of 1.4 ± 0.3 g/(L * h) and 0.25 ± 0.4, respectively. Therefore, a reduction in fermentation time, higher ethanol titer and productivity were demonstrated in the presence of nanoparticles. The application of manganese ferrite nanoparticles shows a beneficial effect on ethanol production. Research focused on the task of defining the mechanism of their action and evaluation of the reuse of biomass immobilized on manganese ferrite in the ethanol production process should be carried out in the future.

Preparation of nanocellulose by hydrolysis with ionic liquids and two-step hydrolysis with ionic liquids and enzymes

2021 ◽  
Vol 116 ◽  
pp. 5-14
Author(s):  
Marta Babicka ◽  
Magdalena Woźniak ◽  
Kinga Szentner ◽  
Sławomir Borysiak ◽  
Krzysztof Dwiecki ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Degree Of Crystallinity ◽  
Cellulolytic Enzyme ◽  
X Ray Diffraction ◽  
Production Methods ◽  
Step Process ◽  
X Ray ◽  
One Step ◽  
Xrd Patterns ◽  
The One

The aim of this study was to compare parameters of nanocellulose obtained by two different procedures: hydrolysis with ionic liquids (1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate) and hydrolysis with ionic liquids in combination with hydrolysis using a cellulolytic enzyme from Trichoderma reesei. Avicel cellulose was treated with two ionic liquids: 1-allyl-3-methylimidazolium chloride (AmimCl) and 1-ethyl 3-methylimidazolium acetate (EmimOAc). In the two-step hydrolysis cellulose after treatment with ionic liquids was additionally hydrolyzed with a solution of enzymes. In order to characterize the obtained material, the following analyses were used: infrared spectroscopy, X-ray diffraction and dynamic light scattering. The results indicated that cellulose obtained by two-step nanocellulose production methods (first hydrolysis with ionic liquids and then with enzymes) showed similar parameters (particle size, XRD patterns and degree of crystallinity) as the material after the one-step process, i.e. hydrolysis with ionic liquids.

Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite

2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno
Keyword(s):  
Magnetic Properties ◽  
Gallic Acid ◽  
Precipitation Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
The Fourier Transform ◽  
The One ◽  
Co Precipitation

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.

X-ray diffraction analysis for thin films of PbTiO3-La2/3TiO3 prepared by the sol-gel method

1994 ◽  
Vol 9 (8) ◽  
pp. 2133-2137 ◽  
Author(s):  
Hideki Yoshioka
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Diffraction Method ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coating Methods ◽  
Diffraction Patterns ◽  
System 1

Thin films in the system (1 - x) PbTiO3−xLa2/3TiO3 were prepared by the sol-gel and dip-coating methods. Phases deposited in the films and the lattice parameters as a function of the composition were investigated by the x-ray diffraction method. The solid solutions with a perovskite structure were formed as a single phase with x up to 0.9. For the composition of x = 1.0, metastable La-Ti-O perovskite phase with a small amount of the impurity phase, La2Ti2O7, was obtained. Simulation of x-ray diffraction patterns based on the defect structure model shows that the structure of the La-Ti-O perovskite phase includes randomly distributed cation vacancies at the A-site, namely (La2/3□1/3)TiO3.

scholarly journals Evolution of the microstructure, residual stresses, and mechanical properties of W–Si–N coatings after thermal annealing

2005 ◽  
Vol 20 (5) ◽  
pp. 1356-1368 ◽  
Author(s):  
A. Cavaleiro ◽  
A.P. Marques ◽  
J.V. Fernandes ◽  
N.J.M. Carvalho ◽  
J.Th. De Hosson
Keyword(s):  
Residual Stress ◽  
Thermal Annealing ◽  
Amorphous Film ◽  
Amorphous Coating ◽  
X Ray Diffraction ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Composition Structure ◽  
The One ◽  
Deposited Film

W–Si–N films were deposited by reactive sputtering in a Ar + N2 atmosphere from a W target encrusted with different number of Si pieces and followed by a thermal annealing at increasing temperatures up to 900 °C. Three iron-based substrates with different thermal expansion coefficients, in the range of 1.5 × 10−6 to 18 × 10−6 K−1 were used. The chemical composition, structure, residual stress, hardness (H), and Young’s modulus (E) were evaluated after all the annealing steps. The as-deposited film with low N and Si contents was crystalline whereas the one with higher contents was amorphous. After thermal annealing at 900 °C the amorphous film crystallized as body-centered cubic α–W. The crystalline as-deposited film presented the same phase even after annealing. There were no significant changes in the properties of both films up to 800 °C annealing. However, at 900 °C, a strong decrease and increase in the hardness were observed for the crystalline and amorphous films, respectively. It was possible to find a good correlation between the residual stress and the hardness of the films. In several cases, particularly for the amorphous coating, H/E higher than 0.1 was reached, which envisages good tribological behavior. The two methods (curvature and x-ray diffraction) used for calculation of the residual stress of the coatings showed fairly good agreement in the results.

Effects of NaNbO3 Crystals on Electrical Properties of K0.5Na0.5NbO3 Ceramics

2016 ◽  
Vol 690 ◽  
pp. 126-130 ◽  
Author(s):  
Chavalit Suksri ◽  
Piewpan Parjansri ◽  
Sutatip Thonglem ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Seed Crystal ◽  
Molten Salt Synthesis ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Structure And Morphology ◽  
Pure Perovskite Phase

Lead-free (K0.5Na0.5)NbO3 (KNN) piezoelectric ceramics were studied and synthesized by the seed-induced method. NaNbO3 crystal was used as seed and prepared by molten salt synthesis (MSS). The average particles size of NaNbO3 seed crystal was about 1-3 mm. Then, the NaNbO3 seed was mixed with KNN powder and ball milled for 24 h. The mixed powder was calcined at 700-900 °C and sintered at 1100 °C. The phase structure and morphology of the ceramics were investigated by X-ray diffraction and scanning electron microscope and the electrical properties were studied. The results indicated that all samples showed a pure perovskite phase. The highest density of the ceramic was 93% compared to the theoretical density. The results showed that NaNbO3seed crystal improved piezoelectric properties of KNN ceramics.

Low-temperature fabrication of pyroelectric Ba0.8Sr0.2TiO3 thin films by a sol-gel process

2001 ◽  
Vol 16 (3) ◽  
pp. 778-783 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Sol Gel Process ◽  
Columnar Grains ◽  
Uncooled Infrared Detectors

Ba0.8Sr0.2TiO3 films were fabricated with a 0.05 M solution by a sol-gel process at temperatures between 550 and 650 °C. Analysis by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy revealed that the films annealed at 650 °C showed pure perovskite phase, tetragonal structure, and columnar grains with an average grain size of 150 nm. Electrical measurements performed on the films annealed at 650 °C showed two dielectric peaks in the dielectric constant–temperature curve, a remnant polarization of 1.4 μC/cm2, a coercive field of 18.3 kV/cm, and good insulating property. The measured pyroelectric coefficient for the films annealed at 650 °C was larger than 3.1 × 10−4 C/m2K at the temperatures ranging from 10 to 26 °C and reached the maximum value of 4.1 × 10−4 C/m2K at 16 °C. The excellent pyroelectric property rendered the Ba0.8Sr0.2TiO3 films annealed at 650 °C promising for uncooled infrared detectors and thermal imaging applications.

Magnetoresistance Effects for the Inhomogeneous Perovskite System of Ag Doped La0.833Na0.167MnO3

2011 ◽  
Vol 110-116 ◽  
pp. 553-558
Author(s):  
Jian Wu
Keyword(s):  
Perovskite Phase ◽  
Inhomogeneous System ◽  
X Ray Diffraction ◽  
Magnetoresistance Effect ◽  
Two Phase ◽  
X Ray ◽  
Magnetoresistance Ratio ◽  
Diffraction Patterns ◽  
System 1 ◽  
Relative Change

The transport properties of the inhomogeneous system (1/4) Ag2O-La0.833Na0.167MnO3(LNMO/Ag) have been systematically studied. X-ray diffraction patterns show that the LNMO/Ag sample is the two-phase composite and consists of a magnetic La0.833Na0.167MnO3(LNMO) perovskite phase and a nonmagnetic Ag metal phase. The resistivity of the sample decreases dramatically with Ag added into the pure perovskite LNMO manganites. For the LNMO/Ag sample, the Curie temperatureTCis 331 ± 2 K and slightly higher than that of the LNMO sample (323 ± 2 K). Due to the dope of Ag metal, the room temperature magnetoresistance effect is enhanced significantly (from 7% for the pure LNMO manganites to 23% for the LNMO/Ag sample under a relative lower field of 0.5 T and from 37.5% for the LNMO sample to 41 % for the LNMO/Ag sample under a high field of 6 T at the temperature of 330 K. In the low temperature regime, the magnetoresistance ratio of the LNMO/Ag sample is smaller than that of the LNMO sample, which is contrary to the magnetoresistance effect in high temperature. The effects are discussed qualitatively by use of a model which is based on the relative change among the intrinsic magnetoresistance effect and the extrinsic magnetoresistance effect.

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