scholarly journals Influence of Processing Conditions on Crystal Structure of Bi6Fe2Ti3O18 Ceramics

2016 ◽  
Vol 61 (2) ◽  
pp. 881-886 ◽  
Author(s):  
A. Lisińska-Czekaj ◽  
M. Lubina ◽  
D. Czekaj ◽  
M. Rerak ◽  
B. Garbarz-Glos ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ambient Air ◽  
Processing Conditions ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Number Of Layers ◽  
Solid State Reaction Route ◽  
Diffraction Patterns

Abstract Aim of the present research was to apply a solid state reaction route to fabricate Aurivillius-type ceramics described with the formula Bi6Fe2Ti3O18 (BFTO) and reveal the influence of processing conditions on its crystal structure. Pressureless sintering in ambient air was employed and the sintering temperatures were 850 and 1080 °C. It was found that the fabricated BFTO ceramics were multiphase ones. They consisted of two Bim+1Fem-3Ti3O3m+3 phases, namely the phase with m=5 (i.e. the stoichiometric phase) and m=4 (i.e. the phase with a reduced number of layers in the slab). Detailed X-ray diffraction patterns analysis showed that both phases adopted the same orthorhombic structure described with Fmm2 (42) space group. The ratio of weight fractions of the constituent phases (m=5): (m=4) was ~30:70.

Crystal Structure of the New Phosphate AgMnPO4

2009 ◽  
Vol 64 (7) ◽  
pp. 875-878 ◽  
Author(s):  
Hamdi Ben Yahia ◽  
Etienne Gaudin ◽  
Jacques Darriet
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Solid State Reaction Route ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Silver Atoms

The new compound AgMnPO4 has been synthesized by a solid-state reaction route. Its crystal structure was determined from single-crystal X-ray diffraction data. AgMnPO4 crystallizes with triclinic symmetry, space group P1̄, a = 9.6710(6), b = 5.695(2), c = 6.629(3) Å , α = 102.55(3), β = 105.85(2), γ = 80.70(2)◦, and Z = 4. Its structure is built up from MnO6, MnO5 and PO4 polyhedra forming tunnels filled with silver atoms.

scholarly journals Deep learning for visualization and novelty detection in large X-ray diffraction datasets

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lars Banko ◽  
Phillip M. Maffettone ◽  
Dennis Naujoks ◽  
Daniel Olds ◽  
Alfred Ludwig
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Artificial Intelligence ◽  
Deep Learning ◽  
Novelty Detection ◽  
Structural Similarity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Post Hoc

AbstractWe apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the structural similarity of textured diffraction patterns. While other artificial intelligence (AI) agents are effective at classifying XRD data into known phases, a similarly conditioned VAE is uniquely effective at knowing what it doesn’t know: it can rapidly identify data outside the distribution it was trained on, such as novel phases and mixtures. These capabilities demonstrate that a VAE is a valuable AI agent for aiding materials discovery and understanding XRD measurements both ‘on-the-fly’ and during post hoc analysis.

COMPOSITION DEPENDENCE OF SUPERCONDUCTIVITY AND CRYSTAL STRUCTURE IN La(Ba1−xCax)2Cu3O7−y SYSTEM

1989 ◽  
Vol 03 (04) ◽  
pp. 307-311 ◽  
Author(s):  
N. CAO ◽  
J.Q. ZHENG ◽  
X.Y. SHAO ◽  
X.S. CHEN ◽  
W.Y. GUAN
Keyword(s):  
Crystal Structure ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Composition Dependence ◽  
Superconducting Transition ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Zero Resistance

The composition dependence of superconductivity and crystal structure in La ( Ba 1−x Ca x)2 Cu 3 O 7−y system was determined by the resistivity measurements and X-ray diffraction analysis. The superconducting transition temperature is raised with the increase of Ca content till x=0.6, at which the zero resistance temperature of the sample is 81.5 K. In the meanwhile, the crystal structure of the sample changed from tetragonal (x=0) to orthorhombic structure (x=0.2, 0.4, 0.6). With further increase of Ca content, the superconductivity decrease for the sample of x=0.8 with mixed phases including the orthorhombic oxygen-deficient perovskite-like (ODP) structure and no superconducting transition is found at 4.2 K for the sample of x=1 without the ODP structure. A possible explanation of these experimental results is given.

CRYSTAL STRUCTURE OF ZIRCONIUM TRICHLORIDE

1964 ◽  
Vol 42 (10) ◽  
pp. 1886-1889 ◽  
Author(s):  
B. Swaroop ◽  
S. N. Flengas
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Main Cell ◽  
Diffraction Patterns

The crystal structure of zirconium trichloride was determined from X-ray diffraction patterns. Zirconium trichloride belongs to the [Formula: see text]space group. The dimensions of the main cell at room temperature are: a = 5.961 ± 0.005 Å and c = 9.669 ± 0.005 Å.The density of zirconium trichloride was measured and gave the value of 2.281 ± 0.075 g/cm3 while, from the X-ray calculations, the value was found to be 2.205 g/cm3.

Effects of Electron Beam on Structure and Physical Properties of Natural Colorless Topaz

2015 ◽  
Vol 1125 ◽  
pp. 60-63
Author(s):  
Chutharat Paikaew ◽  
Juthamas Inthanont ◽  
Adisak Punyanut ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Beam ◽  
Physical Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Function Group ◽  
And Function ◽  
Beam Dose

The purpose of this research was to investigate physical properties, configuration and color of topaz. Topazes were irradiated with electron beam linear accelerator at different dose from 40 to 180 MGy. The color of topaz was analyzed by UV-vis and it was shown that the color of topaz was becoming strong color with increased electron beam dose. Crystal structure and function group of topaz were characterized by X- ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the topaz has orthorhombic structure and no other crystalline. After irradiated, topaz released OH indicating higher crystallinity of topaz and this was confirmed with the results of electron spin resonance (ESR). Electron beam dose response of topaz was investigated. ESR results showed that the Al3+ ion was substituted in Si4+ site and Ti3+ impurity in Al4+ site and this result corresponds to the results of FTIR. The experiment result indicated that electron beam could be making defect on crystal structure and color enhancement of topaz.

Structural and phase equilibria studies in the system Pt-Fe-Cu and the occurrence of tulameenite (Pt2FeCu)

1985 ◽  
Vol 49 (353) ◽  
pp. 547-554 ◽  
Author(s):  
M. Shahmiri ◽  
S. Murphy ◽  
D. J. Vaughan
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Critical Temperature ◽  
Grain Boundary ◽  
Phase Region ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Slow Cooling ◽  
X Ray ◽  
Diffraction Patterns

AbstractThe crystal structure and compositional limits of the ternary compound Pt2FeCu (tulameenite), formed either by quenching from above the critical temperature of 1178°C or by slow cooling, have been investigated using X-ray diffraction, transmission electron microscopy, differential thermal analysis and electron probe microanalysis.The crystal structure of Pt2FeCu, established using electron density maps constructed from the measured and calculated intensities of X-ray diffraction patterns of powdered specimens, has the (000) and (½½0) lattice sites occupied by Pt atoms and the (½0½) and (0½½) sites occupied by either Cu or Fe atoms in a random manner. The resulting face-centred tetragonal structure undergoes a disordering transformation at the critical temperature to a postulated non-quenchable face-centred cubic structure. Stresses on quenching, arising from the ordering reaction, are relieved by twinning along {101} planes or by recrystallization along with deformation twinning; always involving grain boundary fracturing.Phase relations in the system Pt-Fe-Cu have been investigated through the construction of isothermal sections at 1000 and 600°C. At 1000°C there is an extensive single phase region of solid solution around Pt2FeCu and extending to the binary composition PtFe. At 600°C the composition Pt2FeCu lies just outside this now reduced area of solid solution in a two-phase field. Comparison of the experimental results with data for tulameenite suggests that some observed compositions may be metastably preserved. The occurrence of fine veinlets of silicate or other gangue minerals in tulameenite is suggested to result from grain boundary fracturing on cooling below the critical temperature of 1178°C and to be evidence of a magmatic origin.

scholarly journals `Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31

2015 ◽  
Vol 71 (7) ◽  
pp. 807-809 ◽  
Author(s):  
Wilhelm Klein ◽  
Hanpeng Jin ◽  
Viktor Hlukhyy ◽  
Thomas F. Fässler
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Original Structure ◽  
Site Symmetry ◽  
Structure Model ◽  
Reaction Route ◽  
X Ray ◽  
Anisotropic Displacement Parameters ◽  
Solid State Reaction Route ◽  
Atomic Coordinates

The crystal structure of the title compound was previously reported with composition `Pd20Sn13' [Sarahet al.(1981).Z. Metallkd,72, 517–520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtainedviaa solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3):0.62 (3). One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3aand 3b).

The X-Ray Powder Diffraction Patterns and Crystal Structure for Al2M3Y(M=Cu, Ni)

2014 ◽  
Vol 950 ◽  
pp. 48-52
Author(s):  
De Gui Li ◽  
Ming Qin ◽  
Liu Qing Liang ◽  
Zhao Lu ◽  
Shu Hui Liu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Hexagonal Structure ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Arc Melting ◽  
Diffraction Patterns

The Al2M3Y(M=Cu, Ni) compound was synthesized by arc melting under argon atmosphere. The high-quality powder X-ray diffraction data of Al2M3Y have been presented. The refinement of the X-ray diffraction patterns for the Al2M3Y compound show that the Al2M3Y has hexagonal structure, space groupP6/mmm(No.191), with a = b = 5.1618(2) Å, c = 4.1434(1) Å,V= 95.6 Å3,Z= 1,ڑx= 5.7922 g/cm3,F30= 155.5(0.0057, 34), RIR = 2.31 for Al2Cu3Y, and with a = b = 5.0399(1) Å, c = 4.0726(1) Å,V= 89.59 Å3,Z= 1,ڑx= 5.9118 g/cm3,F30= 135.7(0.0072, 30), RIR = 2.54 for Al2Ni3Y.

IMPEDANCE SPECTROSCOPY STUDY OF THE FERROELECTRIC Pb0.8K0.1Dy0.1Nb2O6 CERAMICS

2008 ◽  
Vol 22 (12) ◽  
pp. 1251-1264 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
T. SWARNA LATHA ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD
Keyword(s):  
Room Temperature ◽  
Ferroelectric Ceramic ◽  
Dielectric Anomaly ◽  
Spectroscopy Study ◽  
Conductivity Measurements ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Impedance Spectroscopy Study

Polycrystalline Dy -modified Pb 1-x K 2x Nb 2 O 6 (PKN) ferroelectric ceramic with a general formula Pb 1-x K 2x-3y M y Nb 2 O 6 for x=0.20, y=0.10 and M = Dy , have been prepared by the solid-state reaction route. The X-ray diffraction (XRD) studies of the material at room temperature revealed orthorhombic structure with lattice parameters a=17.701 Å, b=17.958 Å and c=3.883 Å. The dielectric anomaly with a sharp peak is observed at 430°C. The impedance plots are used as a tool to analyze the sample behavior as a function of frequency. The grain and grain boundary contributions are estimated. The modulus mechanism indicates the non-Debye type relaxation. The activation energy value near the phase transition temperature has been found to be different in the above TC from AC conductivity measurements.

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