scholarly journals Synthesis and Structural Study of Ferroelectric Material Lead Titanate (PbTiO3)

2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Avantika Chauhan ◽  
Srishti Paliwal ◽  
S.C Bhatt
Keyword(s):  
Lead Titanate ◽  
Single Phase ◽  
Ferroelectric Material ◽  
Sem Analysis ◽  
Tetragonal Symmetry ◽  
Stoichiometric Ratio ◽  
Single Phase Sample ◽  
Prepared Sample ◽  
Crystalline Nature ◽  
Xrd Techniques

Lead Titanate PbTiO3, (PT) is technologically important ferroelectric and piezoelectric ceramics. To make PbTiO3, the oxides PbO and TiO2 are combined in a stoichiometric ratio. Solid-state reaction process was used to synthesize the oxides. The calcination temperature was 8500C. The prepared sample has been characterized by XRD techniques with a scanning rate of 6 degree per minutes. The prepared sample PbTiO3 shows crystalline nature, with Tetragonal symmetry, as observed by X –ray measurements. A scanning electron microscope (SEM) was used to examine the surface morphology and grain size of the obtained samples. Micrographs obtained from SEM analysis revealed a single phase sample of well-defined grains.

Structural, magnetic and high frequency (1–6 GHz) parameters of Sr-substituted BaFe2O4 monoferrites synthesized by sol–gel method

2019 ◽  
Vol 33 (19) ◽  
pp. 1950219 ◽  
Author(s):  
Mukhtar Ahmad ◽  
Jawaria Shaheen ◽  
Waseem Abbas Hashmi ◽  
Majid Niaz Akhtar ◽  
Muhammad Asif
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Anisotropy Constant ◽  
Dielectric Parameters ◽  
Single Phase Sample ◽  
Heat Treated Sample ◽  
Auto Combustion ◽  
Phase Spinel

In this work, Sr-substituted samples of single-phase spinel monoferrites with chemical formula [Formula: see text] (x = 0.00, 0.33, 0.67, 1.00) were synthesized using sol–gel auto-combustion method. In order to confirm the single-phase formation of these samples, a sample (x = 0.00) was chosen for heat treatment at different temperatures (100, 300, 400, 600 and [Formula: see text]) for 4 h. The heat treated sample was then investigated by X-ray diffraction (XRD) analysis and results showed that a single-phase sample can be successfully synthesized at a temperature of [Formula: see text], which is much lower than that reported in earlier literature for synthesis of same structured samples. All the synthesized samples were then sintered at [Formula: see text] for 4 h to achieve better crystallinity. From XRD patterns, lattice parameters, cell volume and XRD density as a function of Sr-substitution were calculated. Scanning electron microscopy (SEM) results showed that the grain size increased as the temperature was increased. Fourier transform infrared spectroscopy (FTIR) results confirmed the single-phase spinel monoferrites at [Formula: see text]. From M–H loops (x = 0.0, 0.33, 0.67 and 1.00), different magnetic parameters such as saturation magnetization [Formula: see text], remanance [Formula: see text], coercivity [Formula: see text] and magnetic moment [Formula: see text] were calculated. Magnetocrystalline anisotropy constant and Y–K angles of Sr-doped Ba monoferrites were also calculated. In addition, the variation of different dielectric parameters (real permittivity, imaginary permittivity, real permeability, imaginary permeability, ac conductivity and loss tangent) as a function of frequency (1–6 GHz) has been discussed in this work. The results suggest that the synthesized materials have many advantages over previously reported single-phase spinel monoferrites.

scholarly journals Hydroxyapatite/Silver Nanoparticles Powders as Antimicrobial Agent for Bone Replacements

2019 ◽  
Vol 92 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Agnieszka Sobczak-Kupiec ◽  
Dagmara Malina ◽  
Regina Kijkowska ◽  
Wioletta Florkiewicz ◽  
Klaudia Pluta ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Chemical Reduction ◽  
Absorption Spectrometry ◽  
Bactericidal Effect ◽  
Sem Analysis ◽  
Biological Assessment ◽  
Molar Ratio ◽  
In Situ Deposition ◽  
Morphological Modification ◽  
Xrd Techniques

This paper reports a superficial morphological modification of the hydroxyapatite grains obtained by in situ deposition of Ag nanoparticles on natural origin calcium phosphate powder. Ceramic material was prepared in three stage bone treatment, including hydrolysis with a lactic acid, pre-calcination, and proper calcination. Subsequently, the Ag nanoparticles were synthesized by chemical reduction of Ag+ by sodium borohydride in a solution of polyvinylpyrrolidone and in presence of hydroxyapatite. Such-prepared materials were investigated with X-ray diffraction, Fourier-transformed infrared spectroscopy, atomic absorption spectrometry and scanning electron microscopy with energy dispersive spectroscopy. Furthermore, Ca/P molar ratio was calculated and microbiological tests were performed to investigate materials antimicrobial activity. The appearance of Ag nanoparticles located on phosphate surface was confirmed by SEM analysis, and no chemical bonding with hydroxyapatite was recorded by IR and XRD techniques. Additionally, the biological assessment revealed bactericidal effect on Escherichia coli and Staphylococcus aureus, while slightly affected on Enterococcus faecalis viability.

On the tetragonality of the room-temperature ferroelectric phase of barium titanate, BaTiO3

2009 ◽  
Vol 42 (3) ◽  
pp. 480-484 ◽  
Author(s):  
Dean S. Keeble ◽  
Pamela A. Thomas
Keyword(s):  
Barium Titanate ◽  
Diffraction Pattern ◽  
Room Temperature ◽  
Ferroelectric Material ◽  
Tetragonal Symmetry ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Group Assignment ◽  
Growth Method

The room-temperature phase of the important ferroelectric material barium titanate, BaTiO3, was re-investigated by single-crystal X-ray diffraction on a sample grown by the top-seeded solution growth method, with the intention of demonstrating once again that the structure has tetragonal symmetry consistent with the space-group assignmentP4mmand thus resolving recent controversy in the scientific community and literature [Yoshimura, Kojima, Tokunaga, Tozaki & Koganezawa (2006).Phys. Lett. A,353, 250–254; Yoshimura, Morioka, Kojima, Tokunaga, Koganezawa & Tozaki (2007).Phys. Lett. A,367, 394–401]. To this end, the X-ray diffraction pattern of a small (341 µm3) sample of top-seeded solution-grown BaTiO3was measured using an Oxford Diffraction Gemini CCD diffractometer employing Mo Kα radiation and an extended 120 mm sample-to-detector distance. More than 104individual diffraction maxima observed out to a maximum resolution of 0.4 Å were indexed on two tetragonal lattices. These were identical to within the standard deviations on the lattice parameters and were related to each other by a single rotation of 119.7° about the [11\overline1] direction of the first tetragonal lattice (the major twin component), although the actual twinning operation that explains the observed diffraction pattern both qualitatively and quantitatively is shown to be conventional 90° twinning by them[101] operation. Importantly, it is not necessary to invoke either monoclinic symmetry or a coexistence of tetragonal and monoclinic phases to explain the observed diffraction data.

scholarly journals Analysis of Completely Prevaporized Spray Flames with Water/Octane Core/Shell Structured Droplets

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Chung-Yao Hsuan ◽  
Shuhn-Shyurng Hou ◽  
Ta-Hui Lin
Keyword(s):  
Flame Propagation ◽  
Single Phase ◽  
Laminar Flame ◽  
Internal Heat ◽  
Core Shell ◽  
Stoichiometric Ratio ◽  
Liquid Loading ◽  
The Core ◽  
Spray Flames ◽  
Internal Heat Transfer

A series of studies on laminar flame propagation in off-stoichiometric dilute sprays of monodispersed inert or fuel drops had been investigated by large activation energy asymptotics. The present study extends previous theoretical model to consider water/octane core/shell structured drops instead of single-phase drops. The core/shell structured drops are composed of core fluid (water) encased by a layer of shell fluid (n-octane). In this study, we only deal with the case that core/shell structured drops are vaporized completely just at flame location. Namely, the discussions of this paper are restricted to the completely prevaporized mode. By varying parameters of core water radius, core-to-shell ratio, the amount of liquid loading, and the stoichiometric ratio (lean or rich burning), we examine the gasification of core water and shell fuel of core/shell structured drops upstream of the bulk flame and its relation to the internal heat transfer. The effects of drop radius, core-to-shell ratio, liquid loading, and overall heat loss or gain on flame propagation flux are reported and discussed.

Hydrothermal Synthesis and Photoluminescence Properties of Ca(MoO4)x(WO4)(1-X) Microcrystallines

2013 ◽  
Vol 652-654 ◽  
pp. 599-606
Author(s):  
Yan Zhao ◽  
Yan Yan Wei ◽  
Dan Qin ◽  
Xin Lai ◽  
Yun Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Uv Light ◽  
Emission Spectra ◽  
Fluorescence Analysis ◽  
Tetragonal Symmetry ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Structure Surface ◽  
Ft Ir

Ca(MoO4)x(WO4)(1-x)solid solution microcrystallines were synthesized by hydrothermal method at 120 °C; the crystal structure, surface morphology and room temperature photoluminescence properties of the as-synthesized microcrystallines were investigated by through X-ray diffraction (XRD), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR) and fluorescence analysis (FA), respectively. Our results show that the obtained Ca(MoO4)x(WO4)(1-x)microcrystallines are single-phase scheelite structure with tetragonal symmetry. The grain size of the Ca(MoO4)x(WO4)(1-x) microcrystallines gradually increases with the increasing x (except x=0) and their agglomeration also becomes serious with x increasing. Under excited by 245 nm or 280 nm ultraviolet light (UV-light) at room temperature, the emission spectra of the Ca(MoO4)x(WO4)(1-x) microcrystallines vary slightly from 410nm to 490nm with increasing x. Whereas the emission intensity of Ca(MoO4)x(WO4)(1-x) microcrystallines changed markedly, and it increases with the increasing x (x＞0).

Synthesis, Phase Formation and Characterization of Co4Nb2O9 Powders Synthesized by Solid-State Reaction

2008 ◽  
Vol 55-57 ◽  
pp. 873-876 ◽  
Author(s):  
N. Chaiyo ◽  
R. Muanghlua ◽  
A. Ruangphanit ◽  
Wanwilai C. Vittayakorn ◽  
Naratip Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Dwell Time ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Techniques ◽  
Scanning Electron

A corundum-type structure of cobalt niobate (Co4Nb2O9) has been synthesized by a solid-state reaction. The formation of the Co4Nb2O9 phase in the calcined powders was investigated as a function of calcination conditions by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. Morphology and particle size have been determined by scanning electron microscopy (SEM). It was found that the minor phases of unreacted Co3O4 tend to form together with the columbite CoNb2O6 phase at a low calcination temperature and short dwell time. It seems that the single-phase of Co4Nb2O9 in a corundum phase can be obtained successfully at the calcination conditions of 900°C for 60 min, with heating/cooling rates of 20°C /min.

scholarly journals Получение, структура, диэлектрические и магнитные свойства керамики SrFe-=SUB=-2/3-=/SUB=-W-=SUB=-1/3-=/SUB=-O-=SUB=-3-=/SUB=-

2018 ◽  
Vol 60 (3) ◽  
pp. 510
Author(s):  
А.В. Павленко ◽  
А.В. Турик ◽  
Л.А. Шилкина ◽  
С.П. Кубрин ◽  
Ю.B. Русалев ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Solid Phase ◽  
Ceramic Technology ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Phase Reactions ◽  
Perovskite Type ◽  
Perovskite Type Structure

AbstractPolycrystalline samples of SrFe_2/3W_1/3O_3 (SFWO) ceramic were obtained by solid-phase reactions with subsequent sintering using conventional ceramic technology. X-ray diffraction analysis showed that at room temperature, the SFWO ceramic is single-phase and has a perovskite-type structure with tetragonal symmetry and parameters a = 3.941(9) Å, c = 3.955(6) Å, and c/a = 1.0035. In studying the magnetic properties and the Mössbauer effect in SFWO ceramics, it is found that the material is a ferrimagnet, and the iron ions are only in the valence state of Fe^3+. It is suggested that in the temperature range of T = 150–210°C, a smeared phase transition from a cubic (paraelectric) phase to a tetragonal (ferroelectric) phase takes place in SFWO with decreasing temperature.

scholarly journals Feldspar-banana peel composite adsorbent for efficient crude oil removal from solution

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Folasegun A. Dawodu ◽  
Chika J. Abonyi ◽  
Kovo G. Akpomie
Keyword(s):  
Crude Oil ◽  
Oil Spill ◽  
Sem Analysis ◽  
Banana Peel ◽  
X Ray Diffraction ◽  
Hydrophilic Nature ◽  
Oil Concentration ◽  
Pseudo Second Order ◽  
Xrd Techniques ◽  
Kinetics Of

AbstractThe problem of oil spill pollution associated with the transport of crude oil and its products across the globe is of serious concern. The sorption technique has proved to be promising for oil spill treatment but is limited by the hydrophilic nature of most natural organic sorbents. The combo of natural organic and inorganic sorbents have been found to enhance the hydrophobicity for oil sorption. Therefore this study was aimed at the preparation of a novel feldspar-banana peel biochar composite (FBPC) with enhanced hydrophobicity for the sorption of crude oil. The prepared sorbent was characterised by the scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, while the crude oil was characterised using standard methods. Batch sorption was used to determine the effect of contact time (30–150 min), temperature (25–100 °C), pH (2.0–10.0), oil concentration (4.0–12.0 g/L) and sorbent dosage (0.1–0.5 g) on sorption. SEM analysis of FBPC revealed a porous structure, while XRD confirmed the crystalline phases of feldspar. The crude oil samples had pH (6.40–6.60), density (0.960 0 0.962 g/cm3), kinematic viscosity (24.0–27.6 cSt) and API gravity (24.25–24.51°). The Langmuir model with R2 > 0.7781 presented the best fit than the Temkin and Freundlich model in the isotherm analysis, while the pseudo-second-order model with R2 > 0.9711 was applicable in the kinetics of sorption. The thermodynamic analysis revealed a decrease in randomness at the crude oil-FBPC interface. The prepared FBPC was found to be an efficient inorganic–organic composite sorbent with enhanced hydrophobicity for the sorption of crude oil.

Phyllantus Emblica Mediated Silica Nanomaterials: Biosynthesis, Structural and Stability Analysis

2021 ◽  
Author(s):  
M Sankareswaran ◽  
M Vanitha ◽  
P. Rajiv ◽  
A. Anbukumaran
Keyword(s):  
Silica Nanoparticles ◽  
Research Work ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Weight Percentage ◽  
Ir Studies ◽  
Silica Nanomaterials ◽  
Crystalline Nature ◽  
Size Of Particles ◽  
Average Size

Abstract The current investigation reports on a green route, simple and eco-friendly method for synthesis of silica nanoparticles from Phyllantus emblica. Appropriate characterization techniques were employed to assess the crystalline nature, microstructure, size, purity, elemental composition and stability of as-biosynthesized silica nanoparticles. The XRD analysis showed a wide-ranging peak at 22∘ of 2θ value and proved that the nanoparticles were crystalline nature with 32 nm average size of particles. FT-IR studies confirmed the occurrence of metal oxide group and presence of phyto-molecules namely hydroxyl, amide, and carboxyl functional groups, which were responsible for formation and stabilization of silica nanomaterials. TGA and Zeta potential analysis determined that silica nanoparticles are highly thermostable. EDX analysis revealed the purity of nanomaterials and spectra confirmed that formation of silica nanomaterials (72.97 weight percentage of SiO2 content) with low impurities. SEM analysis shows that the particles are spherical in shape with low agglomeration. This research work concluded that the P. emblica was an excellent and reliable green resource for production of highly stable and potential silica nanoparticles.

Synthesis of Bismuth Ferrite and its Application for Oscillator Material up to 25 GHz Range

2021 ◽  
Vol 1028 ◽  
pp. 9-14
Author(s):  
Yeti Rafitasari ◽  
Ardita Septiani ◽  
Asep Ridwan Nugraha ◽  
Ervin Naufal Arrasyid ◽  
Dedi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Bismuth Ferrite ◽  
Sol Gel ◽  
Resonant Peak ◽  
Hysteresis Curve ◽  
Stoichiometric Ratio ◽  
Quenching Process ◽  
Potential Applications ◽  
Wide Potential

Among other multiferroic materials, bismuth ferrite (BiFeO3) attracts much attention due to its room-temperature properties and its wide potential applications. However, the synthesis to obtain a single-phase material is hard to be achieved because of the volatility of bismuth oxide. In this study, the BiFeO3 powders were synthesized by using a sol-gel method from the nitrates of bismuth and iron salt with the various stoichiometric ratios between Bi and Fe of 1:1.02, 1:1, 1.02:1, and 1.03:1. The single-phase and a good stoichiometric ratio of Bi: Fe = 1:1 was obtained from the starting composition ratio of 1.03:1 with a quenching process from 550°C sintering temperature. The single-phase of BiFeO3 shows a hysteresis curve of a weak antiferromagnetic with a coercive field of about 1.38 kOe at room temperature. The measurement of microwave oscillator was measured by using a dielectric resonator from 0 to 25 GHz does not show any resonant peak.

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