Synthesis and Characterization of Sr1−xBaxBi2Ta2O9 Materials

2000 ◽  
Vol 15 (8) ◽  
pp. 1661-1664 ◽  
Author(s):  
R. E. Melgarejo ◽  
M. S. Tomar ◽  
P. S. Dobal ◽  
R. S. Katiyar
Keyword(s):  
Spectroscopic Studies ◽  
Material System ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Complete Solid Solution ◽  
Solid Solution System ◽  
Ferroelectric Memory ◽  
Memory Applications ◽  
Barium Bismuth

Due to its endurance to ferroelectric fatigue, SrBi2Ta2O9 (SBT) has been extensively investigated. We report here the synthesis of Sr1−xBaxBi2Ta2O9 (x = 0.0, 0.1, 0.5, 1.0) using a solution-based route. The precursors used in this work were the salts of strontium, barium, bismuth, and tantalum ethoxide. X-ray diffraction and Raman spectroscopic studies indicated the formation of complete solid solution system for Sr1−xBaxBi2Ta2O9. This material system may provide interesting properties relevant to microwave tuning and ferroelectric memory applications, which are under investigation.

Synthesis and Characterization of the Manganese Pyroarsenate Mn2As2O7 · 2H2O

2001 ◽  
Vol 56 (4-5) ◽  
pp. 359-363 ◽  
Author(s):  
N. Stock ◽  
G. D. Stucky ◽  
A. K. Cheetham
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Mean Value ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Distorted Octahedral ◽  
Ir And Raman ◽  
Hydrothermal Methods

Abstract The manganese pyroarsenate hydrate, Mn2As2O7 · 2 H2O, has been obtained as a single phase product using hydrothermal methods and the structure has been determined by single crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/n with a = 6.6576(4), b = 14.555(1), c = 7.8147(5) Å, β = 94.935(1)°, V = 754.46(8) Å3 and Z = 4. The manganese ions are each coordinated to five oxygen atoms and a water molecule in a distorted octahedral arrangement. Edge-sharing MnO6 octahedra form chains which are connected to a three-dimensional framework by As2O74- ions. The pyroarsenate anion, which attains a nearly eclipsed conformation, has a mean As-O distance for the terminal As-O bonds of 1.669(2) Å, while for the bridging oxygen atom a mean value of 1.757(2) Å is observed. Magnetic susceptibility measurements indicate the presence of high-spin Mn2+ ions. Thermogravimetric as well as IR and Raman spectroscopic studies of Mn2As2O7 · 2 H2O are presented.

Synthesis of Zn1–xMgxO and its structural characterization

2001 ◽  
Vol 16 (4) ◽  
pp. 903-906 ◽  
Author(s):  
M. S. Tomar ◽  
R. Melgarejo ◽  
P. S. Dobal ◽  
R. S. Katiyar
Keyword(s):  
Crystal Structure ◽  
Spin Coating ◽  
Optoelectronic Devices ◽  
Spectroscopic Studies ◽  
Structural Behavior ◽  
Material System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Mg Substitution

Zn1–xMgxO is an important material for optoelectronic devices. We synthesized this material using a solution-based route. We investigated in detail the structural behavior of this material system using x-ray diffraction and Raman spectroscopy. Mg substitution up to x ≈ 0.10 does not change the crystal structure, as revealed by x-ray diffraction and Raman spectroscopic studies. This synthesis route is also suitable to prepare thin films by spin coating with the possibility of p and n doping.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

scholarly journals Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Beata Zielińska ◽  
Ewa Mijowska ◽  
Ryszard J. Kalenczuk
Keyword(s):  
Diffuse Reflectance ◽  
Hydrogen Generation ◽  
Mixed Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Photocatalytic Hydrogen Generation ◽  
Irregular Structure ◽  
Transmission Electron

K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C) on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3and K2Ta4O11were obtained. It was also found that the sample composed of KTaO3and traces of unreacted Ta2O5(annealed at 600°C) exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD) and diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM) and an energy dispersive X-ray spectrometer (EDX) as its mode.

scholarly journals Structural characterization of quaternary selenites of tungsten(VI), A 2W3SeO12 (A = NH4, Cs, Rb, K or Tl)

2021 ◽  
Vol 77 (4) ◽  
pp. 406-411
Author(s):  
Vineela Balisetty ◽  
Kanamaluru Vidyasagar
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Solid State Reactions ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Compound K ◽  
Three Dimensional Structure ◽  
Thermal And Spectroscopic Studies ◽  
Anionic Framework

The quaternary A 2W3SeO12 (A = NH4, Cs, Rb, K or Tl) selenites have been prepared in the form of single crystals by hydrothermal and novel solid-state reactions. They were characterized by X-ray diffraction, thermal and spectroscopic studies. All of them have a hexagonal tungsten oxide (HTO) related [W3SeO12]2− anionic framework with pyramidally coordinated Se4+ ions. The known A 2W3SeO12 (A = NH4, Cs or Rb) compounds are isostructural with the Cs2W3TeO12 compound and have a non-centrosymmetric layered structure containing intra-layer Se—O bonds. The new compound K2W3SeO12(α) is isostructural with the K2W3TeO12 compound and has a centrosymmetric three-dimensional structure containing interlayer Se—O bonds. It is inferred that the new Tl2W3SeO12 compound has the same three-dimensional structure as K2W3SeO12(α).

scholarly journals X-ray diffraction and Raman spectroscopic studies of Zn-substituted carrboydite-like compounds

2006 ◽  
Vol 100 (1) ◽  
pp. 174-186 ◽  
Author(s):  
Yu-Hsiang Lin ◽  
Moses O. Adebajo ◽  
J. Theo Kloprogge ◽  
Wayde N. Martens ◽  
Ray L. Frost
Keyword(s):  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic

Electrical and Raman Spectroscopic Studies on Aurivillius Layered-Pervoskite Ceramics

2019 ◽  
Vol 1154 ◽  
pp. 80-90
Author(s):  
Mohammed Abdul Basheer ◽  
Vagmare Gangadhar ◽  
Guduru Prasad ◽  
Gobburu Subramanya Kumar ◽  
Nandi Venkata Prasad
Keyword(s):  
Rare Earth ◽  
Complex Impedance ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Solid State Route ◽  
A Site ◽  
Rare Earth La

Double rare-earth (La; Sm/Gd) substituted Aurivillius family of Bismuth Layered Structured Ferroelectrics (BLSF) namely Bi2.6Sm0.2La0.2TiNbO9 (BSLT; sample-A), Bi2.6Gd0.2La0.2TiNbO9 (BGLT; sample-B), single phase ceramics were prepared by solid state route. In addition, intergrowth (x BSLT - (1-x) BGLT, where x=0.49; sample-C) and solid solution (BSLT­x - BGLTy; where x + y=0.4; sample-D) materials were prepared. Dielectric, ferroelectric and Raman spectroscopic properties were studied on the said above materials. The X-ray diffraction analysis and Raman spectra revealed well-formation of stable structure. Though, the sample-C and sample-D have lower coercive field, compared to the sample-A and sample-B, but they exhibited sharp hysterisis loop. Therefore the instrinsic defects of sample-D inhabits more sensitivity towards the ferroelectric behaviour. The results were corroborated to the impedance and dielectrical data. The results were consistent with the SEM micrographs and complex impedance plots. An attempt is made to understand the effect of rare-earth ions on A-site of layered-pervoskite structure, defined as: (Bi2O2)2+(An-1BnO3n+1)2-.The term n represents number of pervoskite blocks interleaved with the bismuth oxide layers.

Characterization of porous titania glass: Raman, x-ray diffraction and x-ray photoelectron spectroscopic studies

1992 ◽  
Vol 23 (3) ◽  
pp. 161-166 ◽  
Author(s):  
Yee Hong Chee ◽  
R. P. Cooney ◽  
R. F. Howe ◽  
P. A. W. van der Heide
Keyword(s):  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Titania

Synthesis, crystal structure and physicochemical characterization of a Hg(II) complex with 6-methoxyquinoline as ligand

2015 ◽  
Vol 70 (10) ◽  
pp. 719-725 ◽  
Author(s):  
Cristian Villa-Pérez ◽  
Isabel C. Ortega ◽  
Angélica M. Payán-Aristizábal ◽  
Gustavo Echeverría ◽  
Gloria C. Valencia-Uribe ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Theoretical Calculations ◽  
Physicochemical Characterization ◽  
Spectroscopic Studies ◽  
Monoclinic Space Group ◽  
Oxygen Production ◽  
X Ray Diffraction ◽  
Singlet Molecular Oxygen ◽  
X Ray

AbstractA new complex of Hg(II) with 6-methoxyquinoline (C10H9NO-6MQ) has been synthesized and characterized. The structure of the complex Hg(6MQ)Cl2 was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c with a = 3.9139(3), b = 26.3400(2), c = 10.9090(9) Å, β = 89.833(6)°, V = 1124.6(1) Å3 and Z = 4 molecules per unit cell. The coordination geometry of the mercury(II) center can be described as a distorted square pyramid formed by one nitrogen atom of the 6MQ and four chlorine atoms. Fourier transform infrared, Raman and UV/Vis spectroscopic studies have been carried out to characterize the compound, using theoretical calculations for the assignment of the experimentally observed bands. The thermal behavior was investigated by thermogravimetric analysis. The quantum yield of singlet molecular oxygen production ΦΔ was measured with steady-state methods in ethanol, using 9,10-dimethylanthracene (DMA) as actinometer and Bengal rose as reference photosensitizer. The resultant singlet molecular oxygen was detected indirectly by photooxidation reactions of DMA. The luminescence properties have also been studied.

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