THE XRD STUDY OF THE EFFECT OF SLIGHT CHANGE IN STRUCTURE ON THE SUPERCONDUCTIVITY OF Y-Ba-Cu-O SYSTEM MATERIAL

In this paper the differences in diffraction intensities from some crystal planes in the X-ray diffraction patterns of high Tc Y-Ba-Cu-O system superconductors prepared by different processing conditions and the difference among various structure cells in references are interpreted using computer fitting. The results suggest that there exists two structure cells in the single phase YBa2Cu3O7−x samples. Both structure cells have the same crystal symmetry and almost the same lattice parameters, a=3.821Å, b=3.892Å and c=11.676Å, but the different distortion degree of Cu2-O plane. According to EPR spectra measured on the same samples, it is considered that the improvement of superconductivity for the samples prepared by two-step annealing in flowing oxygen may be related to concentration of the structure cell with more serious distortion on the Cu2-O plane.

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Ferroelectricity in SrTiO3 Ceramics Induced by Pr Doping

MRS Proceedings ◽

10.1557/proc-848-ff9.19 ◽

2004 ◽

Vol 848 ◽

Author(s):

A. Durán ◽

E. Martínez ◽

J. Mata ◽

J. Heiras ◽

X. Solans ◽

...

Keyword(s):

Single Phase ◽

Temperature Differential ◽

X Ray Diffraction ◽

Ionic Radii ◽

Ferroelectric State ◽

X Ray ◽

The Difference ◽

Diffraction Patterns ◽

A Site ◽

Srtio3 Ceramics

ABSTRACTFerroelectricity was induced in SrTiO3 by the Sr exchange for Pr ion in the A site of the perovskite ABO3-type structure. X-ray diffraction patterns show single phase crystalline structure in the SrxPr1-xTiO3 compound for x=0, 0.025, 0.050, 0.075 and 0.1 compositions. Rietveld refinement shows that the unit cell volume decreases with the increasing of Pr content as a consequence of the difference between Sr/Pr ionic radii. Furthermore, high-temperature differential thermoanalysis (DTA) displays a small anomaly at about 118 °C which is probably due to the Pr ion producing a distortion of the perovskite structure via an off-center site. This deformation in the lattice induces a measurable polar behavior of the solid solution. Dielectric permittivity (ε vs T) measurements display a well defined peak at about 238 °C. Furthermore, a well defined hysteresis loop at 30 °C with a remnant polarization that tends to decrease with increasing Pr concentration is observed. Both experimental results confirm the ferroelectric state induced by the Pr ion.

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Infrared spectroscopic study of the YPO4-YCrO4 system

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852139 ◽

1985 ◽

Vol 50 (10) ◽

pp. 2139-2145

Author(s):

Alexander Muck ◽

Eva Šantavá ◽

Bohumil Hájek

Keyword(s):

Spectroscopic Study ◽

Infrared Spectra ◽

Point Of View ◽

Mixed Crystals ◽

Crystal Symmetry ◽

Infrared Spectroscopic Study ◽

X Ray Diffraction ◽

X Ray ◽

Infrared Spectroscopic ◽

Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

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Ferromagnetic Order in the Intermetallic Alloys laNi5-xMgx

ASEAN Journal on Science and Technology for Development ◽

10.29037/ajstd.49 ◽

2012 ◽

Vol 29 (1) ◽

pp. 50

Author(s):

D.N Ba ◽

L.T Tai ◽

N.T Trung ◽

N.T Huy

Keyword(s):

Magnetic Properties ◽

Curie Temperature ◽

Room Temperature ◽

Single Phase ◽

Chemical Doping ◽

Intermetallic Alloys ◽

X Ray Diffraction ◽

X Ray ◽

Ferromagnetic Order ◽

Diffraction Patterns

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ≤ 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.

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Analysis of Selected Area Diffraction Patterns With Winjade

Microscopy and Microanalysis ◽

10.1017/s1431927600021838 ◽

1998 ◽

Vol 4 (S2) ◽

pp. 342-343 ◽

Cited By ~ 1

Author(s):

S. D. Walck ◽

P. Ruzakowski-Athey

Keyword(s):

Single Phase ◽

Xrd Analysis ◽

Analysis Program ◽

X Ray Diffraction ◽

Program Module ◽

Vast Number ◽

One Dimensional ◽

X Ray ◽

Diffraction Patterns ◽

Xrd Patterns

The analysis of Selected Area Diffraction (SAD) patterns that are collected from a single phase material having sufficient crystallites to provide continuous rings is relatively straightforward. However, when this condition is not met and there may be several phases present having rings of a spotty nature, the pattern is complex and can be quite difficult to analyze manually because of the vast number of discrete spots. WinJade from MDI is an X-ray diffraction (XRD) analysis program with an Electron Diffraction Program Module (EDPM) that can be used to aid in the analysis of SAD patterns. The EDPM produces Integrated Circular Density Plots (ICDP), which are one-dimensional intensity profiles plotted as a function of equivalent XRD 20 values or crystal d-spacings. These ICDP's can be overlayed with XRD patterns or with reference lines from the NIST and JCPDS crystalline databases for direct comparisons.

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Degradation of phenol by using magnetic photocatalysts of titania

Water Science & Technology ◽

10.2166/wst.2013.669 ◽

2013 ◽

Vol 67 (7) ◽

pp. 1434-1441 ◽

Cited By ~ 1

Author(s):

Chiung-Fen Chang ◽

I.-Peng Tseng

Keyword(s):

Heat Treatment ◽

Photocatalytic Activity ◽

Single Phase ◽

Health Impacts ◽

X Ray Diffraction ◽

Final Temperature ◽

Soaking Time ◽

X Ray ◽

Green Materials ◽

Diffraction Patterns

Magnetic TiO2 (MT) composites were prepared and applied to degrading phenol, which is one of the listed priority pollutants. The effects of heat treatment under preparation on the photocatalytic activity of MT composites have been investigated by varying the soaking time under a constant final temperature of 823 K. The total organic carbon and ring-remaining intermediates of o-DHB, p-DHB and 1,4-BQ in solution were detected during the photodegradation of phenol. All the resulting MT composites were the single-phase anatase and magnetite judged by X-ray diffraction patterns. The calcination of the as-prepared particles was proven to be extremely crucial to the photocatalytic activity. The best condition of heat treatment was found to be soaking time of 2 h at T = 823 K due to the good performance of photocatalytic activity, stable magnetic property, and reusability over three times. The results lead to the conclusion that recyclable MT composites prepared in this study, which belonged to the category of recyclable green materials, exhibit good photocatalytic activity to degrade phenol so as to possess applicable potential for the degradation of refractory organics in the aqueous solution. Furthermore, the environmental and health impacts were reduced as MT composites were applied in the treatment of water pollution.

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Influence of Processing Conditions on Crystal Structure of Bi6Fe2Ti3O18 Ceramics

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0149 ◽

2016 ◽

Vol 61 (2) ◽

pp. 881-886 ◽

Cited By ~ 2

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.

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Evidence for cooling-rate-dependent icosahedral short-range order in a Cu–Zr–Al metallic glass

Journal of Applied Crystallography ◽

10.1107/s1600576714021232 ◽

2014 ◽

Vol 47 (6) ◽

pp. 1906-1911 ◽

Cited By ~ 5

Author(s):

Helmut Hermann ◽

Uta Kühn ◽

Horst Wendrock ◽

Valentin Kokotin ◽

Björn Schwarz

Keyword(s):

Metallic Glass ◽

Cooling Rate ◽

Short Range ◽

X Ray Diffraction ◽

X Ray ◽

Rate Dependent ◽

Icosahedral Clusters ◽

Thermal Displacements ◽

The Difference ◽

Diffraction Patterns

Samples of Cu47.5Zr47.5Al5metallic glass were prepared at different cooling rate,R. The dependence of the X-ray diffraction patterns onRwas analysed by comparing them with corresponding patterns of computer-simulated models generated at different cooling rates as well. The observed changes in the experimental diffraction patterns are reproduced by the simulations, showing an increasing fraction of icosahedral clusters with decreasing cooling rate. The difference of the fractions of icosahedrally coordinated atoms in mould-cast and rapidly quenched Cu47.5Zr47.5Al5averages to 3 (1)%. Different frozen-in thermal displacements and different density are ruled out as a possible origin for the experimental observations.

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Reduced-pressure MOCVD of highly crystalline BaTiO3 thin films

Journal of Materials Research ◽

10.1557/jmr.1992.0542 ◽

1992 ◽

Vol 7 (3) ◽

pp. 542-545 ◽

Cited By ~ 26

Author(s):

Peter C. Van Buskirk ◽

Robin Gardiner ◽

Peter S. Kirlin ◽

Steven Nutt

Keyword(s):

Thin Films ◽

Electron Diffraction ◽

Total Pressure ◽

Single Phase ◽

X Ray Diffraction ◽

Reduced Pressure ◽

X Ray ◽

Selected Area Electron Diffraction ◽

Diffraction Patterns ◽

First Time

Epitaxial BaTi3 films have been grown on NdGaO3 [100] substrates by reduced pressure MOCVD for the first time. The substrate temperature was 1000 °C and the total pressure was 4 Torr. Electron and x-ray diffraction measurements indicate highly textured, single phase films on the NdGaO3 substrate which are predominantly [100], with [110] also present. TEM and selected area electron diffraction (SAED) indicate two specific orientational relationships between the [110] and the [001] diffraction patterns.

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The stability and screw sense of the α -helix in poly- β -benzyl-L-aspartate

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1960.0214 ◽

1960 ◽

Vol 259 (1296) ◽

pp. 110-128 ◽

Cited By ~ 87

Keyword(s):

Optical Rotatory Dispersion ◽

Molecular Models ◽

X Ray Diffraction ◽

X Ray ◽

Left Handed ◽

The Difference ◽

Diffraction Patterns ◽

The Stability ◽

Α Helix ◽

The Right

A number of polymers and copolymers containing β -benzyl-L-aspartate has been prepared and their optical rotatory dispersion in a variety of solvents has been measured. The results of these measurements together with studies of infra-red spectra, X-ray diffraction patterns, deuteration rates and molecular models lead to the following conclusions. (i) The α -helical form of poly- β -benzyl-L-aspartate is considerably less stable relative to the solvated randomly coiled form than that of poly- γ -benzyl-L-glutamate. (ii) The left-handed α -helix of poly- β -benzyl-L-aspartate is more stable than the right-handed one. (iii) The difference in stability between the two senses of α -helix is much less in the case of poly- β -benzyl-L-aspartate than in that of poly- γ -benzyl-L-glutamate or poly-L-alanine.

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