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.

scholarly journals Двухфазность кристаллической структуры твердых растворов (1-x)PbFe-=SUB=-2/3-=/SUB=-W-=SUB=-1/3-=/SUB=-O-=SUB=-3-=/SUB=--xPbTiO-=SUB=-3-=/SUB=- (x=0.25,0.3,0.35) при комнатной температуре

2021 ◽  
Vol 91 (1) ◽  
pp. 72
Author(s):  
Н.В. Зайцева ◽  
А.А. Набережнов ◽  
Е.П. Смирнова
Keyword(s):  
Crystal Structure ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Solid Solutions ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Lead Ions ◽  
X Ray Diffraction ◽  
X Ray

The evolution of the crystal structure of (1-x) PbFe2 / 3W1 / 3O3 - хPbTiO3 solid solutions depending on the PbTiO3concentrations (at x = 0.25, 0.3, 0.35) in the region of the morphotropic phase boundary was studied using x-ray diffraction at room temperature. It was established that all three compositions are a mixture of cubic and tetragonal phases, and an increase in the concentration of PbTiO3 above 30 mol. % leads to an increase of the tetragonal phase contribution. The parameters of the crystal structure and the content of both phases in these solid solutions are determined. It was shown that at room temperature there are static displacements of lead ions from the principle crystallographic positions.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

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.

Phase Diagram of the W-doped Pb(Zn1/3Nb2/3)O3–BaTiO3– PbTiO3 System Around a Morphotropic Phase Boundary Composition

2002 ◽  
Vol 17 (5) ◽  
pp. 1085-1091 ◽  
Author(s):  
W. Z. Zhu ◽  
M. Yan ◽  
A. L. Kholkin ◽  
P. Q. Mantas ◽  
J. L. Baptista
Keyword(s):  
High Temperature ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical Neutrality ◽  
Phase Boundary Composition ◽  
A Site ◽  
Successive Phase

The morphotropic phase boundary (MPB) composition that is characterized by the coexistence of rhombohedral and tetragonal phases in the Pb(Zn1/3Nb2/3)O3–BaTiO3– PbTiO3 system was modified by W-doping at the B site of a perovskite structural block. To maintain the electrical neutrality, creation of A-site vacancies was intentionally introduced in the formulation of the examined compositions. Incorporation of W ions was revealed to stabilize the tetragonal phase against the rhombohedral one, shifting the MPB toward the PZN-rich end at room temperature. High-temperature x-ray diffraction examination in combination with dielectric measurements discloses two successive phase transitions as a sample is cooled from high temperature, namely, paraelectric cubic to ferroelectric rhombohedral followed by ferroelectric rhombohedral to ferroelectric tetragonal. W addition appears to suppress the first transition while promoting the second one.

scholarly journals The phase diagram of a mixed halide (Br, I) hybrid perovskite obtained by synchrotron X-ray diffraction

RSC Advances ◽  
2019 ◽  
Vol 9 (20) ◽  
pp. 11151-11159 ◽  
Author(s):  
Frederike Lehmann ◽  
Alexandra Franz ◽  
Daniel M. Többens ◽  
Sergej Levcenco ◽  
Thomas Unold ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Phase Separation ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Perovskite

The phase diagram elucidates structural changes and phase separation effects, induced by halide substitution in hybrid perovskite MAPb(I,Br)3 solid solution.

Solid solutions in the system Ag2S–Ag2Se

1992 ◽  
Vol 7 (8) ◽  
pp. 2219-2224 ◽  
Author(s):  
N.E. Pingitore ◽  
B.F. Ponce ◽  
M.P. Eastman ◽  
F. Moreno ◽  
C. Podpora
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Type Structure ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
Compositional Gradient ◽  
X Ray ◽  
Optical Electron ◽  
Discrete Phase ◽  
Diffraction Peaks

Optical, electron microprobe, and x-ray diffraction analysis of 88 samples of various compositions between Ag2S and Ag2Se synthesized at high temperature in sealed quartz tubing indicates the presence of two solid-solution series in this system at ambient (room) conditions. One series extends from Ag2S to approximately Ag2S0.4Se0.7 and has the Ag2S-III-type structure (monoclinic). The second series ranges from Ag2S0.3Se0.7 to Ag2Se and is characterized by the Ag2Se-II-type structure (orthorhombic). Members of both series, in appropriate proportions, characterize the apparent compositional gap between the two solid solutions. Gradual shifts in the locations of the x-ray diffraction peaks along the compositional gradient of each solid solution revealed an expansion of the d-spacing as the larger Se ion was substituted for S in the Ag2S-III-type structure and a contraction as S was substituted for Se in the Ag2Se-II-type structure. The reported discrete phase, Ag4SSe (aguilarite, orthorhombic), appears to be simply a member of the monoclinic Ag2S-III-type solid solution.

Structural changes of Ce–Pr–O oxides in hydrogen: a study by in situ X-ray diffraction and Raman spectroscopy

2003 ◽  
Vol 13 (12) ◽  
pp. 3017-3020 ◽  
Author(s):  
Sylvie Rossignol ◽  
Francois Gérard ◽  
Danielle Mesnard ◽  
Charles Kappenstein ◽  
Daniel Duprez
Keyword(s):  
Raman Spectroscopy ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
X Ray

Microstructure and electrical properties of 0.5PZN-0.5PZT relaxor ferroelectrics close to the morphotropic phase boundary

2009 ◽  
Vol 24 (6) ◽  
pp. 2029-2034 ◽  
Author(s):  
Lu-Yang Zhao ◽  
Yu-Dong Hou ◽  
Li-Min Chang ◽  
Man-Kang Zhu ◽  
Hui Yan
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Oxygen Vacancies ◽  
Rhombohedral Phase ◽  
Relaxor Ferroelectrics ◽  
Arrhenius Law ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Mixing Method

Relaxor ferroelectrics of Pb(Zn1/3Nb2/3)0.5(Zr0.47Ti0.53)0.5O3 (0.5PZN-0.5PZT) were prepared using the conventional oxide mixing method. Both x-ray diffraction analysis and Raman spectroscopy indicate that the amounts of rhombohedral phase are close to tetragonal phase, implying the presence of the morphotropic phase boundary (MPB) in the system of 0.5PZN-0.5PZT, and this result was further confirmed by transmission electron microscopy (TEM) micrographs. At MPB composition, the excellent piezoelectric properties, such as kp (0.66) and d33 (425pC/N), were obtained due to the more possible polarization directions of domains and high dc resistivity of 6.5 × 1010 Ω·cm. Meanwhile, the dielectric studies revealed that the indicator of the degree of diffuseness γ value is 1.73, implying that the relaxor nature of the 0.5PZN-0.5PZT is ceramic. The activation energy related to the dc conductivity was estimated from a linear fitting of the Arrhenius law. The value of 0.09 and 1.04 eV for low and high temperature range corresponds well to the activation energies of migration and first ionization of the oxygen vacancies.

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