scholarly journals FERROELECTRIC PROPERTIES OF BaBi4Ti4O15 DOPED WITH Pb2+, Al3+, Ga3+, In3+, Ta5+ AURIVILLIUS PHASES

2010 ◽  
Vol 9 (3) ◽  
pp. 398-403
Author(s):  
Afifah Rosyidah ◽  
Djulia Onggo ◽  
Khairurrijal Khairurrijal ◽  
Ismunandar Ismunandar
Keyword(s):  
Rietveld Refinement ◽  
Ferroelectric Properties ◽  
Random Access ◽  
Diffraction Method ◽  
Atomic Scale ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Aurivillius Phases ◽  
Cell Parameters ◽  
Aurivillius Oxides

In recent years, the ferroelectric properties of aurivillius oxides have attracted interest and an extensive amount of work has been done toward the realization of their potential application in nonvolatile memories (FeRAM: ferroelectric random access memory). Recently, we have carried out computer simulation in atomic scale in order to predict the energies associated with the accommodation of aliovalent and isovalent dopants (Pb2+, Al3+, Ga3+, In3+, Ta5+) in the aurivillius structure of BaBi4Ti4O15. In this work, the predicted stable phases were synthesized using solid state reactions and their products then were characterized using powder X-ray diffraction method. The cell parameters were determined using Rietveld refinement in orthorhombic system with space group of A21am. Results from the ferroelectric properties measurement of BaBi4Ti4O15 were also presented. The cell parameters for BaBi4Ti4O15 doped with Pb2+, Al3+, Ga3+,In3+, Ta5+ were a = 5.47116(4) b = 5.45636(5) c = 41.8649(3) Å; a = 5.47104(4) b = 5.45634(4) c = 41.8640(3) Å; a = 5.47112(4) b = 5.45648(4) c = 41.8643(3) Å; a = 5.47111(4) b = 5.45645(5) c = 41.8649(3) Å; and a = 5.47134(4) b = 5.45588(4) c = 41.8639(5) Å. The ferroelectric properties measurement for BaBi4Ti4O15 doped with Pb2+, Al3+, Ga3+,In3+, Ta5+ showed that the Pr = 15.225 mC/cm2, Ec = 33.96 kV/cm; Pr = 15.925 mC/cm2, Ec = 35.724 kV/cm; Pr = 16.625 mC/cm2, Ec = 36.504 kV/cm; Pr = 15.57 mC/cm2, Ec = 32.925 kV/cm; Pr = 17.2827 mC/cm2, Ec = 37.44 kV/cm.   Keywords: Aurivillius phase; Rietveld refinement; Ferroelectric properties; BaBi4Ti4O15

Fabrication of Bi6Fe2Ti3O18 Ceramics by Mixed Oxide Method

2012 ◽  
Vol 730-732 ◽  
pp. 100-104
Author(s):  
Agata Lisińska-Czekaj
Keyword(s):  
Room Temperature ◽  
Ceramic Powder ◽  
Diffraction Method ◽  
Elementary Cell ◽  
X Ray Diffraction ◽  
Stoichiometric Mixture ◽  
Pressing Method ◽  
X Ray ◽  
Cell Parameters ◽  
Ceramic Samples

In the present study Bi6Fe2Ti3O18 (BFTO) ceramics has been fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, TiO2 and Fe2O3. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements have shown conservation of the chemical composition of the ceramic powder after calcination. Hot-pressing method was used for final densification of ceramic samples. The crystalline structure of the sintered samples was examined by X-ray diffraction method at room temperature. It was found that BFTO ceramics sintered at T=980 °C adopted the orthorhombic structure of Aba2 (41) space group with the following elementary cell parameters: a=5.4567(2)Å, b=49.418(2) and c=5.4826(2). Details concerning the atom’s positions are presented.

X-ray diffraction studies of rapid cooled Al-V and Al-Fe-V alloys

2019 ◽  
Vol 1 (96 extended issue) ◽  
pp. 5-11
Author(s):  
O. Shved ◽  
S. Mudry ◽  
V. Girzhon ◽  
O. Smolyakov
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Amorphous Matrix ◽  
Diffraction Method ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Rapid Cooling ◽  
X Ray ◽  
Cell Parameters ◽  
Nonequilibrium Conditions

Purpose: of this paper is to deep and more complete knowledge about the features of phase and structure formation in Al-based alloys with transition metals (TM) Fe and V at rapid cooling from melt. It is known, that nonequilibrium synthesis conditions of such alloys lead to quasicrystalline, amorphous or metastable phases formation, which can significantly improve the physical-chemical properties and first of all the mechanical ones. But understanding of compositional dependences of structure features at formation under nonequilibrium conditions and the correlation of these dependences with physical properties of alloys is far to be clear. Design/methodology/approach: Structure of Al-enriched Al-V, Al-V-Fe rapid cooled alloys was studied by X-ray diffraction method. In order to estimate the influence of structural state of alloy on the mechanical properties the integral microhardness was studied by Vickers method. Findings: Two quasicrystalline icosaedral phases with different cell parameters are revealed in ternary alloys Al100-3xV2xFex (x=2-4). Increasing of transition metal content promotes the formation of phase with higher quasicell parameter embedded in amorphous matrix. With increasing of the transition elements total content from 6 up to 12 at. % the microhardness of alloys increased gradually from 867 to 3050 MPa. Research limitations/implications: Research of nonequilibrium alloys revealed crystalline structure of Al-V alloys and quasicrystalline embedded in amorphous matrix of Al-Fe-V ternary alloys. Obtained results suppose that further structure and physical properties studies of Al-Fe-V alloys will allows to find the conditions to control the producing of materials with desired properties. Practical implications: Using of rapid cooling method for synthesis of Al-enriched Al-Fe-V alloys give an opportunity to produce alloys with significantly improved mechanical properties. Originality/value: Nonequilibrium conditions of cooling allow significantly changes the structure and properties.

scholarly journals Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. Rajesh ◽  
B. Milton Boaz ◽  
P. Praveen Kumar
Keyword(s):  
Single Crystals ◽  
Vickers Microhardness ◽  
Diffraction Method ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal.

Solid-state reaction of Pt thin film with single-crystal (001) β–SiC

1994 ◽  
Vol 9 (3) ◽  
pp. 648-657 ◽  
Author(s):  
J.S. Chen ◽  
E. Kolawa ◽  
M-A. Nicolet ◽  
R.P. Ruiz ◽  
L. Baud ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Single Crystal ◽  
Atomic Scale ◽  
Solid State Reactions ◽  
Main Reaction ◽  
Main Reaction Product ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Interlayer

Thermally induced solid-state reactions between a 70 nm Pt film and a single-crystal (001) β-SiC substrate at temperatures from 300 °C to 1000 °C for various time durations are investigated by 2 MeV He backscattering spectrometry, x-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and cross-sectional transmission electron microscopy. Backscattering spectrometry shows that Pt reacts with SiC at 500 °C. The product phase identified by x-ray diffraction is Pt3Si. At 600–900 °C, the main reaction product is Pt2Si, but the depth distribution of the Pt atoms changes with annealing temperature. When the sample is annealed at 1000 °C, the surface morphology deteriorates with the formation of some dendrite-like hillocks; both Pt2Si and PtSi are detected by x-ray diffraction. Samples annealed at 500–900 °C have a double-layer structure with a silicide surface layer and a carbon-silicide mixed layer below in contact with the substrate. The SiC—Pt interaction is resolved at an atomic scale with high-resolution electron microscopy. It is found that the grains of the sputtered Pt film first align themselves preferentially along an orientation of {111}Pt//{001}SiC without reaction between Pt and SiC. A thin amorphous interlayer then forms at 400 °C. At 450 °C, a new crystalline phase nucleates discretely at the Pt-interlayer interface and projects into or across the amorphous interlayer toward the SiC, while the undisturbed amorphous interlayer between the newly formed crystallites maintains its thickness. These nuclei grow extensively down into the substrate region at 500 °C, and the rest of the Pt film is converted to Pt3Si. Comparison between the thermal reaction of SiC-Pt and that of Si–Pt is discussed.

scholarly journals Engineered Layer-Stacked Interfaces Inside Aurivillius-Type Layered Oxides Enables Superior Ferroelectric Property

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 710 ◽  
Author(s):  
Shujie Sun ◽  
Xiaofeng Yin
Keyword(s):  
Single Phase ◽  
Ferroelectric Properties ◽  
Solid State Reactions ◽  
Layered Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Phase Compound ◽  
Layer Sample ◽  
Lattice Distortions

Layer engineering with different layer numbers inside Aurivillius-type layered structure, similar to interface engineering in heterojunctions or superlattices, can give rise to excellent physical properties due to the correlated layer-stacked interfaces of two different layer phases with different strain states. In this work, using the solid-state reactions from Aurivillius-type Bi3TiNbO9 (2-layer) and Bi4Ti3O12 (3-layer) ferroelectric powder mixtures, single-phase compound of Bi7Ti4NbO21 with an intergrowth structure of 2-layer and 3-layer perovskite slabs sandwiched between the Bi-O layers was synthesized and the effects of this layer-engineered strategy on the structure, Raman-vibration and ferroelectric properties were systematically investigated. The mostly-ordered intergrowth phase was observed clearly by utilizing X-ray diffraction and advanced electron micro-techniques. Uniformly dispersions and collaborative vibrations of Ti and Nb ions in the layer-engineered Bi7Ti4NbO21 were demonstrated. Remarkably, dielectric and ferroelectric properties were also recorded and an enhanced ferroelectric response was found in the layer-engineered mixed-layer sample with high ferroelectric Curie temperature, compared with the homogeneous 2-layer and 3-layer samples. Analyses of the Raman spectra and atomic structures confirmed that the performance improvement of the layer-engineered sample is intrinsic to the correlated layer-stacked interfaces inside the Aurivillius-type layered oxides, arising from strain-induced lattice distortions at the interfaces.

Characterization of the adducts of bis(O-isoamyldithiocarbonato) nickel(II) with heterocyclic amines and X-ray structure of bis(O-isoamyldithiocarbonato)-bis(3-bromopyridine)nickel(II)

2016 ◽  
Vol 57 (8) ◽  
pp. 1688
Keyword(s):  
Magnetic Susceptibility ◽  
Spectral Data ◽  
Metal Ion ◽  
Diffraction Method ◽  
Bidentate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Infrared Spectral ◽  
Substituted Pyridines

A series of six-coordinated Ni(II) complexes, with the general formula Ni(Xan)L2 (where Xan = isoamyldithiocarbonato and L = 2-bromopyridine, 3-bromopyridine, 4-acetylpyridine, 3-hydroxypyridine and 2-methoxypyridine) are synthesized and characterized by the elemental analysis and various physicochemical techniques such as magnetic susceptibility and conductivity measurements, UV-visible and infrared spectral data. Based on the electronic spectra and magnetic susceptibility measurements, an octahedral geometry is proposed for all the complexes. IR spectral data show that in all these complexes substituted pyridines coordinate to the metal ion through nitrogen atoms occupying the fifth and sixth axial positions, whereas O-alkyldithiocarbonate acts as a monoanion bidentate ligand and occupies the planar positions of octahedral structures. The structure of the adduct with 3-bromopyridine is elucidated by the single crystal X-ray diffraction method. The complex crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.5855(4) Å, b = 9.4984(6) Å, c = 12.4518(8) Å, α = 87.944(5)°, β = 78.843(5)°, γ = 77.794(5)°. The crystal structure of the molecule is stabilized by intermolecular C—H…S and C—H…π interactions.

XRD diffraction data and Rietveld refinement of Na8[Si6Al6O24]Cl2

2009 ◽  
Vol 24 (1) ◽  
pp. 41-43 ◽  
Author(s):  
Guilherme Oliveira Siqueira ◽  
Érica Gonçalves Gravina ◽  
Jackson Antônio Lamounier Camargos Resende ◽  
Nelson Gonçalves Fernandes
Keyword(s):  
Infrared Spectroscopy ◽  
Rietveld Refinement ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Alkaline Complex ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Xrd Diffraction ◽  
Bending Modes

A natural sodalite from the geological site Alkaline Complex of Floresta Azul, Bahia, Brazil, has been characterized by electron microprobe, infrared spectroscopy, and powder high-resolution X-ray diffraction techniques. The mineral is an aluminosilicate framework, formed by cages called sodalite unity. Although the sample is natural, the chemical analysis reveals that it is indeed the end member sodalite sensu strictu, Na8[Si6Al6O24]Cl2. Infrared spectroscopy shows Si, Al tetrahedral-oxygen stretching nonsymmetric mode, stretching symmetric mode, and bending modes. Indexing of the experimental X-ray diffraction pattern led to cubic space group P-43n, and unit-cell parameters: a=8.8767(7) Å, Dx=2.301 g cm−3, and V=699.46(1) Å3. X-ray diffraction data are reported. Rietveld refinement was also performed, and the confidence factors are Rp=0.079, Rwp=0.118, and χ2=2.19. The structure of the minerals of sodalite group holds four different tetrahedra: AlO4, ClNa4, Na(ClO3), and SiO4, with Al, Cl, Na, and Si located at the center of each tetrahedron.

Improved powder X-ray data for cancrinites IV: Franzinite

2001 ◽  
Vol 16 (4) ◽  
pp. 216-219 ◽  
Author(s):  
Paolo Ballirano ◽  
Adriana Maras
Keyword(s):  
Rietveld Refinement ◽  
X Ray Diffraction ◽  
Parallel Beam ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Figures Of Merit ◽  
Powder Diffractometer

Improved powder X-ray diffraction (XRD) data for franzinite, the ten-layer member of the cancrinite group of minerals, were obtained using an automated parallel-beam powder diffractometer with a capillary mount. The cell parameters of franzinite were found to be a=12.8976(3) Å, c=26.5040(8) Å, V=3818.2(2) Å3 in space group P321, while the strongest reflections were at 3.725(100), 3.809(65), 3.562(56), 3.586(55), 2.662(42), 2.150(31) and 3.302(30) Å. The new results include an increased number of indexed peaks, improved figures-of-merit with respect to PDF 30-1170 and intensities validated by Rietveld refinement.

scholarly journals Crystal structure and powder X-ray diffraction data of the super-paramagnetic compound CuFeInTe3

2021 ◽  
Vol 67 (2 Mar-Apr) ◽  
pp. 305
Author(s):  
G. E. Delgado ◽  
P. Grima-Gallardo ◽  
J. A. Aitken ◽  
H. Cabrera ◽  
J. Cisterna ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Diffraction Data ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Quaternary Compound ◽  
X Ray ◽  
Cell Parameters ◽  
Figures Of Merit

The crystal structure of the new CuFeInTe3 quaternary compound was studied by the Rietveld method from powder X-ray diffraction data. The CuFeInTe3 compound crystallize in the tetragonal CuFeInSe3-type structure with space group P2c (Nº 112), and unit cell parameters a = 6.1842(1) Å, c = 12.4163(2) Å, V = 474.85(1) Å3. The density of CuFeInTe3 is rx = 5.753 g cm−3. The reliability factors of the Rietveld refinement results are Rp= 5.5%, Rwp= 6.1%, Rexp= 4.7%, and S= 1.3. The powder XRD data of CuFeInTe3 are presented and the figures of merit of indexation are M20 = 79.4 and F30 = 43.3 (0.0045, 154).

scholarly journals Rb-=SUB=-1-x-=/SUB=-Cs-=SUB=-x-=/SUB=-NO-=SUB=-3-=/SUB=- (x=0.025, 0.05, 0.1) монокристаллы и их исследование методом высокотемпературной рентгенографии

2018 ◽  
Vol 52 (6) ◽  
pp. 565
Author(s):  
А.Ф. Хазиева ◽  
В.И. Насиров ◽  
Ю.Г. Асадов ◽  
Ю.И. Алыев ◽  
С.Г. Джабаров ◽  
...  
Keyword(s):  
Melting Point ◽  
Room Temperature ◽  
Diffraction Method ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Transformation Temperatures ◽  
X Ray ◽  
Cell Parameters

AbstractPolymorphic transformations in Rb_0.975Cs_0.025NO_3, Rb_0.950Cs_0.05NO_3, and Rb_0.90Cs_0.1NO_3 crystals grown by us have been studied by the X-ray diffraction method. Four different modifications are found for crystals in the range from room temperature to the melting point. The transformation temperatures and the unit-cell parameters are determined for the crystals of these modifications.

Sign in / Sign up

Export Citation Format

Share Document