scholarly journals Effect of Structural Changes on the Electrical Properties of Sol-gel derived Iron Doped Barium Titanate

2021 ◽  
Vol 2070 (1) ◽  
pp. 012054
Author(s):  
Devendra Singh ◽  
Anju Dixit ◽  
Pramod S Dobal
Keyword(s):  
Barium Titanate ◽  
Structural Changes ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Tangent Loss ◽  
Ionic Radii ◽  
Average Grain Size ◽  
Iron Doped ◽  
The Difference ◽  
Diffraction Patterns

Abstract BaTi1-xFexO3 compositions for x = 0.0 - 0.5 were successfully synthesized using solgel method and the structural, dielectric, ferroelectric, and ferromagnetic properties of these compositions were studied. X-Ray diffraction patterns revealed a tetragonal phase in x=0.0 composition which changed to the hexagonal phase in x = 0.4 and 0.5 compositions. The co-existence of tetragonal and hexagonal phases was observed in iron doped samples up to x= 0.3. The difference in ionic radii of Ti and Fe ions was responsible for changing c/a ratio. Average grain size was found gradually increasing with Fe content in these compositions and was also observed in SEM micrographs. The dielectric constant and tangent loss were found decreasing with Fe concentration. The values of remnant and saturation polarizations decreased whereas that of saturation magnetization increased with an increasing content of Fe in barium titanate.

Structure and Magneto-Resistance in Nanostructured Sr2Fe1-xCrxMoO6 (0≤x≤0.3) Double Perovskite Componds

2011 ◽  
Vol 130-134 ◽  
pp. 3298-3301
Author(s):  
Xiang Hu Li ◽  
Dan Li
Keyword(s):  
Grain Size ◽  
Sol Gel ◽  
Double Perovskite ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
X Ray ◽  
Average Grain Size ◽  
Diffraction Patterns ◽  
Magneto Resistance ◽  
Fe Substitution

The compounds of Fe substitution of Cr in nanotructured Sr2Fe1-xCrxMoO6(0≤x≤0.3) double perovskite have been prepared by sol-gel method. The x-ray diffraction patterns of the samples show that the samples are in nanometer range. And the average grain size D for these samples is 39.7, 37.1, 33.4, 31.9, and 31.2nm, respectively, decreases with the increasing of Cr ion. The saturation magnetization and the magnetoresistance of the samples decrease with the increasing of Cr for the disorder defects which increase for the close ionic radii of Mo and Cr.

Dielectric Properties of Barium Titanate Ceramics Modified by CuO in Different Methods

2012 ◽  
Vol 463-464 ◽  
pp. 276-280 ◽  
Author(s):  
Dan Su ◽  
Yu Wang ◽  
Wan Ping Chen ◽  
Helen Lai Wah Chan ◽  
Li Na Bing
Keyword(s):  
Barium Titanate ◽  
Curie Temperature ◽  
Perovskite Phase ◽  
Hexagonal Phase ◽  
Boundary Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Perovskite Phase ◽  
The Difference ◽  
Titanate Ceramics

CuO has been doped solely and together with BaO and SiO2 into barium titanate by mixing and calcination. X-ray diffraction showed that the sample doped by CuO-BaO has stable second hexagonal phase while the samples doped by CuO, CuO-SiO2 were of a pure perovskite phase. For CuO-BaO doping, the Curie temperature was decreased accompanied with higher εmax; while for CuO doping and CuO-SiO2 codoping, the Curie temperature was increased with εmax decreased. The difference can be explained considering that Cu2+ ion could not only incorporate into the BaTiO3 lattice, but also assemble in the boundary phase when CuO was doped solely. Besides, the mechanisms of CuO doping and SiO2 doping could happen at one time.

scholarly journals Deducing fast electron density changes in randomly orientated uncrystallized biomolecules in a pump–probe experiment

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130332 ◽  
Author(s):  
K. Pande ◽  
P. Schwander ◽  
M. Schmidt ◽  
D. K. Saldin
Keyword(s):  
Electron Density ◽  
Correlation Functions ◽  
Structural Changes ◽  
Direct Calculation ◽  
Difference Electron Density ◽  
Time Resolved ◽  
Pump Probe ◽  
The Difference ◽  
Diffraction Patterns ◽  
Pump Probe Experiment

We propose a method for deducing time-resolved structural changes in uncrystallized biomolecules in solution. The method relies on measuring the angular correlations of the intensities, when averaged over a large number of diffraction patterns from randomly oriented biomolecules in solution in a liquid solvent. The experiment is somewhat like a pump–probe version of an experiment on small angle X-ray scattering, except that the data expected by the algorithm are not just the radial variation of the averaged intensities. The differences of these correlation functions as measured from a photoexcited and dark structure enable the direct calculation of the difference electron density with a knowledge of only the dark structure. We exploit a linear relation we derive between the difference in these correlation functions and the difference electron density, applicable for small structural changes.

Crystallization of barium titanate thin films synthesized via sol-gel processing

1995 ◽  
Vol 53 ◽  
pp. 258-259
Author(s):  
M. C. Gust ◽  
N. D. Evans ◽  
M. L. Mecartney
Keyword(s):  
Thin Films ◽  
Barium Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Independent Films ◽  
X Ray ◽  
Fine Grained ◽  
Diffraction Patterns ◽  
Gel Processing ◽  
Alkoxide Precursors

Sol-gel processing of oxide thin films offers the potential to generate different microstructures by varying process parameters such as water of hydrolysis, chemical precursor, or substrate. For this work, barium titanate (BaTiO3) thin films were prepared by the sol-gel method in order to try and generate different microstructures for dielectric measurements. However, for BaTiOs prepared using alkoxide precursors, the final microstructures of the films were found to be almost process independent. Films using different precursors, different substrates, and different amounts of water of hydrolysis all showed similar TEM microstructures. All the films after final heat treatment were polycrystalline, nanoporous, and randomly oriented BaTiO3; they were also fine-grained, with an average uniform grain size of 25-50 nm (Fig. 1). This fine-grained microstructure has also been observed in other studies of sol-gel derived BaTiO3 thin films. In addition to BaTiO3, electron diffraction patterns showed the presence of trace amounts of rutile TiO2 that were not observed by x-ray diffraction (XRD).

Correlation between Structural and Morphological Properties of multilayer perovskite ZnTiO3 coated porous silicon

2021 ◽  
Author(s):  
Hammedi khadija ◽  
Marouan Khalifa ◽  
M. Consuelo Alvarez –Galvan ◽  
Ezzaouia Hatem
Keyword(s):  
Porous Silicon ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Electrochemical Anodization ◽  
Spherical Particles ◽  
Morphological Properties ◽  
Sem Image ◽  
Number Of Layers ◽  
Average Grain Size ◽  
P Type

This work reports on correlation between structural and morphological properties of ZnTiO3/ porous silicon (PS). The PS were elaborated by electrochemical anodization from the single-crystal p-type silicon wafer. Nanocrystalline ZnTiO3 thin films have been prepared on PS using sol-gel spin coating technique. The deposited films were annealed in air at 800 °C for two hours. The structural, and morphological properties of the films were studied for different number of layers. X-ray diffraction spectra confirms that ZnTiO3 films were hexagonal phase and the crystallite size of ZnTiO3 films increased from 120.56 nm to 125.45nm when the number of layers increase from 4 to 8 layers. SEM image shows approximate semi-spherical particles with a little agglomeration for all samples. The morphologies changed and the average grain size changed and increase from 81nm to 131nm.

Structural and Magnetic Properties of Cobal Ferrite - Barium Titanate Nanotube Arrays

2011 ◽  
Vol 1368 ◽  
Author(s):  
Dario Bueno-Baques ◽  
Veronica Corral-Flores ◽  
Norma A. Morales-Carrillo ◽  
Alejandro Torres ◽  
Hector Camacho-Montes ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Barium Titanate ◽  
Composite Structures ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Nanotube Arrays ◽  
Ferromagnetic Behavior ◽  
Titanate Nanotube ◽  
Average Grain Size ◽  
Composite Nanotubes

ABSTRACTCobalt Ferrite/Barium Titanate nanotube arrays were obtained in anodic aluminum oxide templates (AAO) of 100 nm pore diameter by a two step sol-gel process. Each phase was grown in several wetting – drying cycles starting from the cobalt ferrite layers with the barium titanate on top. As-dried composite structures were sintered at 700 C. The composite nanotubes showed a fine polycrystalline microstructure with an average grain size of 5 nm. The formation of both spinel and perovskite structures was verified by High Resolution Transmission Electron Microscopy (HR-TEM) on isolated nanotubes. The growing rate by layer was found to be lower for the BaTiO3 on top of CoFe2O4 than the later on top of the AAO. Wall sizes were estimated by Z-contrast as 9.8 nm for one layer of CoFe2O4 and 6.6 nm for six layers of BaTiO3. Magnetic properties were studied by VSM. Samples showed ferromagnetic behavior with low coercive values. By means of a finite element model the deformation and stress on the piezoelectric phase was estimated and used to simulate the magnetization reversal under stress in the composite nanotubes, using an updated micromagnetic framework to include the magnetostriction effect. Simulation results showed that a curling mode is expected with opposite vortex states at the end of the nanotubes. The change in the vortex domain structure under voltage driven applied stress is presented and discussed.

scholarly journals Indexing the Diffraction Patterns and Investigating the Crystal Structure of Pb-doped Strontium Ferrites

2013 ◽  
Vol 5 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Z. Ullah ◽  
S. Atiq ◽  
S. Naseem
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Ignition ◽  
Ray Density ◽  
Diffraction Patterns

Strontium hexaferrites were prepared in powder form by sol-gel auto-ignition technique and Pb was doped in different concentrations to attain the various compositions Sr1-xPbxFe12O19 (x = 0.00, 0.05, 0.10, 0.15, 0.20). Sintering treatment of the samples was made at 800 oC for the development of stable hexagonal phase. X-ray diffraction analysis of the samples was carried out for the confirmation and determination of crystal structure of the material. Data obtained from X-ray diffraction analysis helped in determining various parameters of the samples like lattice parameters, volume of the unit cell, crystallite size, bulk density of the samples, X-ray density and porosity of the samples.Keywords:Ferrites; Sol-gel method; X-Ray diffraction; Crystal structure.© 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i2.11578           J. Sci. Res. 5 (2), 235-244 (2013)

Effects of Sm and Mn Co-Doping on Structural and Optical Properties of BiFeO3 Thin Films Prepared by Sol-Gel Technique

2015 ◽  
Vol 815 ◽  
pp. 149-153 ◽  
Author(s):  
Wen Liang Zhou ◽  
Hong Mei Deng ◽  
Jun He ◽  
Jian Liu ◽  
Hui Yi Cao ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Average Grain Size ◽  
Gel Technique ◽  
Diffraction Patterns ◽  
Quartz Substrates ◽  
Rhombohedral Perovskite Structure

(Bi1-xSmx)(Fe0.95Mn0.05)O3(x=0.00, 0.03 and 0.06) thin films were deposited on the quartz substrates by sol-gel technique. The results of X-ray diffraction patterns indicated all thin films had rhombohedral perovskite structure. Moreover, the Sm and Mn co-doping at A-and B-site of BiFeO3resulted in the structural distortion. Scanning electron microscope measurements exhibited that the uniform surface morphology could be obtained by co-doping and the average grain size of the films decreased with increasing Sm content. Furthermore, the fundamental absorption edges ofxBSFMO films showed a blue shift with the increase of Sm content which can be observed in transmittance spectra. The optical band gap of the thin films forx= 0.00, 0.03 and 0.06 can be expressed by (0.84x+2.62) eV, which is due to the Burstein-Moss effect.

Ferroelectricity in SrTiO3 Ceramics Induced by Pr Doping

2004 ◽  
Vol 848 ◽  
Author(s):  
A. Durán ◽  
E. Martínez ◽  
J. Mata ◽  
J. Heiras ◽  
X. Solans ◽  
...  
Keyword(s):  
Single Phase ◽  
Temperature Differential ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
Ferroelectric State ◽  
X Ray ◽  
The Difference ◽  
Diffraction Patterns ◽  
A Site ◽  
Srtio3 Ceramics

ABSTRACTFerroelectricity was induced in SrTiO3 by the Sr exchange for Pr ion in the A site of the perovskite ABO3-type structure. X-ray diffraction patterns show single phase crystalline structure in the SrxPr1-xTiO3 compound for x=0, 0.025, 0.050, 0.075 and 0.1 compositions. Rietveld refinement shows that the unit cell volume decreases with the increasing of Pr content as a consequence of the difference between Sr/Pr ionic radii. Furthermore, high-temperature differential thermoanalysis (DTA) displays a small anomaly at about 118 °C which is probably due to the Pr ion producing a distortion of the perovskite structure via an off-center site. This deformation in the lattice induces a measurable polar behavior of the solid solution. Dielectric permittivity (ε vs T) measurements display a well defined peak at about 238 °C. Furthermore, a well defined hysteresis loop at 30 °C with a remnant polarization that tends to decrease with increasing Pr concentration is observed. Both experimental results confirm the ferroelectric state induced by the Pr ion.

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