An x-ray diffraction and Raman spectroscopy investigation of A-site substituted perovskite compounds: the (Na1-xKx)0.5Bi0.5TiO3(0lexle1) solid solution

2000 ◽  
Vol 12 (14) ◽  
pp. 3267-3280 ◽  
Author(s):  
J Kreisel ◽  
A M Glazer ◽  
G Jones ◽  
P A Thomas ◽  
L Abello ◽  
...  
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Site

scholarly journals Structural and Raman Vibrational Studies ofCeO2-Bi2O3Oxide System

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
L. Bourja ◽  
B. Bakiz ◽  
A. Benlhachemi ◽  
M. Ezahri ◽  
J. C. Valmalette ◽  
...  
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Phase Changes ◽  
Phase System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vibrational Studies ◽  
Coprecipitation Route

A series of ceramics samples belonging to theCeO2-Bi2O3phase system have been prepared via a coprecipitation route. The crystallized phases were obtained by heating the solid precursors at600∘Cfor 6 hours, then quenching the samples. X-ray diffraction analyses show that forx<0.20a solid solutionCe1−xBixO2−x/2with fluorine structure is formed. For x ranging between 0.25 and 0.7, a tetragonalβ′phase coexisting with the FCC solid solution is observed. For x ranging between 0.8 and 0.9, a new tetragonalβphase appears. Theβ′phase is postulated to be a superstructure of theβphase. Finally, close tox=1, the classical monoclinicα Bi2O3structure is observed. Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.

Deposition of TRISO Particles With Superhard SiC Coatings and the Characterization of Anisotropy by Raman Spectroscopy

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
E. López-Honorato ◽  
P. J. Meadows ◽  
J. Tan ◽  
Y. Xiang ◽  
P. Xiao
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Pyrolytic Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Substrate ◽  
High Concentrations ◽  
Triso Particles ◽  
Sic Coatings

In this work we have deposited silicon carbide (SiC) at 1300°C with the addition of small amounts of propylene. The use of propylene and high concentrations of methyltrichlorosilane (9 vol %) allowed the deposition of superhard SiC coatings (42 GPa). The superhard SiC could result from the presence of a SiC–C solid solution, undetectable by X-ray diffraction but visible by Raman spectroscopy. Another sample obtained by the use of 50 vol % Argon, also showed the formation of SiC with good properties. The use of a flat substrate together with the particles showed the importance of carrying out the analysis on actual particles rather than in flat substrates. We show that it is possible to characterize the anisotropy of pyrolytic carbon by Raman spectroscopy.

scholarly journals Size Isn’t Everything - Compositional Variation in Hybrid Organic-Inorganic Lead Halide Perovskites: Kinetically- versus Thermodynamically-controlled Synthesis

2021 ◽  
Author(s):  
Jiyu Tian ◽  
Eli Zysman-Colman ◽  
Finlay Morrison
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Compositional Variation ◽  
X Ray Diffraction ◽  
Solid Solution Formation ◽  
X Ray ◽  
H Nmr ◽  
Halide Perovskites ◽  
A Site ◽  
Lead Halide

<p>The formation and study of a partial solid solution <a></a><a>Az<sub>1-<i>x</i></sub>FA<i><sub>x</sub></i>PbBr<sub>3</sub></a>, using ‘similar’ sized cations azetidinium (Az<sup>+</sup>) and formamidinium (FA<sup>+</sup>), was explored via mechanosynthesis and precipitation synthesis. The composition and lattice parameters of samples from both syntheses were analysed by <sup>1</sup>H NMR and Rietveld refinement of the powder X-ray diffraction. A clear mismatch in the composition of the perovskite was found between the precipitated samples and the corresponding solutions. Such a mismatch was not observed for samples obtained via mechanosynthesis. The discrepancy suggests products are kinetically-controlled during precipitation, compared to thermodynamically-controlled mechanosynthesis. Furthermore, the cell volume as a function of composition in both 6H (Az-rich) and 3C (FA-rich) solid solutions suggests that FA<sup>+</sup> is actually smaller than Az<sup>+</sup>, contradicting the literature. In the 3C (Az-poor) solid solutions, the extent of Az<sub>1-<i>x</i></sub>FA<i><sub>x</sub></i>PbBr<sub>3 </sub>is unexpectedly smaller than Az<sub>1-<i>x</i></sub>MA<i><sub>x</sub></i>PbBr<sub>3</sub>, again in contradiction to the expectation based on the reported cation sizes. These results indicate that other factors, as yet unidentified, must also contribute to the solid solution formation of organic-inorganic hybrid perovskites, not simply the relative sizes of the A-site cations.</p>

scholarly journals Structural and electromechanical study of Bi0.5Na0.5TiO3-BaTiO3 solid-solutions

2013 ◽  
Vol 7 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Biswanath Parija ◽  
Tanmaya Badapanda ◽  
Pratap Sahoo ◽  
Manoranjan Kar ◽  
Pawan Kumar ◽  
...  
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Solid Solutions ◽  
Structural Changes ◽  
Boundary Region ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray

Solid solution of (1-x)Bi0.5Na0.5TiO3-xBaTiO3 have been synthesized via conventional solid-state reaction route. Structural changes of the solid-solutions were investigated by using X-ray diffraction, Rietveld refinement Raman spectroscopy and piezoelectric studies. X-ray diffraction analysis shows a distinct 002/200 peak splitting appearing at x = 0.07 showing the coexistence of rhombohedral and tetragonal phase. Raman spectroscopy shows a splitting of (TO3) mode at x = 0.07 confirming the presence of the morphotropic phase boundary region. The dominant bands in the Raman spectra are analyzed by observing the changes in their respective peak positions, widths and intensities as the x increases. The piezoelectric properties of the solid solution increase with rise in BaTiO3 content and shows optimum value at x = 0.07 owing to the co-existence of two ferroelectric phases. Based on these results, it is suggested that the morphotropic phase boundary in the studied system lies in the composition x = 0.07.

Raman and dielectric response of BaTi1-x(Mg1/3Nb2/3)xO3 solid solution

2013 ◽  
Vol 03 (04) ◽  
pp. 1350030 ◽  
Author(s):  
Jingji Zhang ◽  
Ludong Ji ◽  
Jiangying Wang
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Raman Spectroscopy ◽  
Dielectric Response ◽  
Critical Concentration ◽  
Structural Evolution ◽  
Dielectric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermally Activated

Structural evolution and dielectric analysis have been performed for BaTi 1-x( Mg 1/3 Nb 2/3)x O 3 solid solutions with x ≤ 0.07, together with the analysis of Raman spectroscopy. X-Ray diffraction and Raman results show a structural evolution from a tetragonal phase to a cubic one with increasing x. Dielectric analysis reveals a low critical concentration corresponding to ferroelectric–relaxor crossover (xc = 0.05). Activation energy with dozens meV is obtained using the Vogel–Fulcher relationship, which is attributed to thermally activated off-center ion hopping.

scholarly journals Synthesis of Hf-C-N ceramics by spark plasma sintering

2019 ◽  
Vol 196 ◽  
pp. 00012
Author(s):  
Alexey Zavjalov ◽  
Evgeniy Papynov ◽  
Oleg Shichalin ◽  
Pavel Nikiforov ◽  
Evgenii Goncharov
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Spark Plasma Sintering ◽  
Oxide Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Oxygen Impurities

We obtained the Sample by the spark plasma sintering (SPS) of commercially available HfC and HfN powders. The identification of obtained material was carried out by the X-ray diffraction and the Raman spectroscopy. The solid solution of previous material was confirmed. However oxide phase excreted wile sintering presumably duo to oxygen impurities of used commercially powders.

Deposition of TRISO Particles With Superhard SiC Coatings and the Characterization of Anisotropy by Raman Spectroscopy

2008 ◽  
Author(s):  
Eddie Lo´pez-Honorato ◽  
Philippa J. Meadows ◽  
Jun Tan ◽  
Yang Xiang ◽  
Ping Xiao
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Substrate ◽  
High Concentrations ◽  
Triso Particles ◽  
Sic Coatings

In this work we have deposited SiC at 1300°C with the addition of small amounts of propylene. The use of propylene and high concentrations of methyltrichlorosilane (9 vol%) allowed the deposition of superhard SiC coatings (42 GPa). The superhard SiC could result from the presence of a SiC-C solid solution, undetectable by X-ray diffraction but visible by Raman spectroscopy. Another sample obtained by the use of 50 vol% Argon, also showed the formation of SiC with good properties. The use of a flat substrate together with the particles showed the importance of carrying out the analysis on actual particles rather than in flat substrates. We show that it is possible to characterize the anisotropy of PyC by Raman spectroscopy.

scholarly journals Size Isn’t Everything - Compositional Variation in Hybrid Organic-Inorganic Lead Halide Perovskites: Kinetically- versus Thermodynamically-controlled Synthesis

2021 ◽  
Author(s):  
Jiyu Tian ◽  
Eli Zysman-Colman ◽  
Finlay Morrison
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Compositional Variation ◽  
X Ray Diffraction ◽  
Solid Solution Formation ◽  
X Ray ◽  
H Nmr ◽  
Halide Perovskites ◽  
A Site ◽  
Lead Halide

<p>The formation and study of a partial solid solution <a></a><a>Az<sub>1-<i>x</i></sub>FA<i><sub>x</sub></i>PbBr<sub>3</sub></a>, using ‘similar’ sized cations azetidinium (Az<sup>+</sup>) and formamidinium (FA<sup>+</sup>), was explored via mechanosynthesis and precipitation synthesis. The composition and lattice parameters of samples from both syntheses were analysed by <sup>1</sup>H NMR and Rietveld refinement of the powder X-ray diffraction. A clear mismatch in the composition of the perovskite was found between the precipitated samples and the corresponding solutions. Such a mismatch was not observed for samples obtained via mechanosynthesis. The discrepancy suggests products are kinetically-controlled during precipitation, compared to thermodynamically-controlled mechanosynthesis. Furthermore, the cell volume as a function of composition in both 6H (Az-rich) and 3C (FA-rich) solid solutions suggests that FA<sup>+</sup> is actually smaller than Az<sup>+</sup>, contradicting the literature. In the 3C (Az-poor) solid solutions, the extent of Az<sub>1-<i>x</i></sub>FA<i><sub>x</sub></i>PbBr<sub>3 </sub>is unexpectedly smaller than Az<sub>1-<i>x</i></sub>MA<i><sub>x</sub></i>PbBr<sub>3</sub>, again in contradiction to the expectation based on the reported cation sizes. These results indicate that other factors, as yet unidentified, must also contribute to the solid solution formation of organic-inorganic hybrid perovskites, not simply the relative sizes of the A-site cations.</p>

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