X-ray powder diffraction and magnetic study of nominal Zn1-xNdxCr2Se4 – compounds (x = 0.05, 01)

2013 ◽  
Vol 28 (S2) ◽  
pp. S75-S85
Author(s):  
Izabela Jendrzejewska ◽  
Paweł Zajdel ◽  
Ewa Maciążek ◽  
Maria Sozańska ◽  
Tomasz Goryczka
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Powder Diffraction ◽  
Magnetic Moments ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Antiferromagnetic Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Matrix

Polycrystalline compounds in the Zn1-xNdxCr2Se4 system were prepared by solid state reaction using selenides (ZnSe, Cr2Se3) and pure elements (Nd, Se) as starting materials. The structural properties were determined by X-ray diffraction and the chemical composition confirmed by SEM-EDX. The observed symmetry is cubic, space group Fd3m, while the lattice parameter varies from 10.4955(7)Å to 10.4976(7)Å, and is larger than for the pure matrix. The solubility limit for the current synthesis route lies below x = 0.1. The magnetic moments, effective and saturation, increase with increasing amount of Nd ions. The Neel temperature TN and ΘCW drop, respectively, to 17.4K and 81K for x = 0.1, independently indicating that neodymium is incorporated into the spinel lattice and promotes antiferromagnetic coupling between the Cr3+ ions.

Measurement of Mass Absorption Coefficients Using Compton-Scattered Cu Radiation in X-ray Diffraction Analysis

1990 ◽  
Vol 34 ◽  
pp. 325-335 ◽  
Author(s):  
Steve J. Chipera ◽  
David L. Bish
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Absorption Coefficient ◽  
Mass Absorption Coefficient ◽  
X Rays ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
Solid State Detector ◽  
X Ray ◽  
Mass Absorption

AbstractThe mass absorption coefficient is a useful parameter for quantitative characterization of materials. If the chemical composition of a sample is known, the mass absorption coefficient can be calculated directly. However, the mass absorption coefficient must be determined empirically if the chemical composition is unknown. Traditional methods for determining the mass absorption coefficient involve measuring the transmission of monochromatic X-rays through a sample of known thickness and density. Reynolds (1963,1967), however, proposed a method for determining the mass absorption coefficient by measuring the Compton or inelastic X-ray scattering from a sample using Mo radiation on an X-ray fluorescence spectrometer (XRF). With the recent advances in solid-state detectors/electronics for use with conventional powder diffractometers, it is now possible to readily determine mass absorption coefficients during routine X-ray diffraction (XRD) analyses.Using Cu Kα radiation and Reynolds’ method on a Siemens D-500 diffractometer fitted with a Kevex Si(Li) solid-state detector, we have measured the mass absorption coefficients of a suite of minerals and pure chemical compounds ranging in μ/ρ from graphite to Fe-metal (μ/ρ = 4.6-308 using Cu Kα radiation) to ±4.0% (lσ). The relationship between the known mass absorption coefficient and the inverse count rate is linear with a correlation coefficient of 0.997. Using mass absorption coefficients, phase abundances can be determined during quantitative XRD analysis without requiring the use of an internal standard, even when an amorphous component is present.

A Review of X-Ray Diffraction Methods for Diffusion Studies

1973 ◽  
Vol 17 ◽  
pp. 395-415
Author(s):  
J. A. Carpenter ◽  
D. R. Tenney
Keyword(s):  
Solid State ◽  
Lattice Parameter ◽  
Solid State Diffusion ◽  
X Ray Diffraction ◽  
X Ray ◽  
State Diffusion ◽  
Diffusion Studies ◽  
Parameter Spread ◽  
Non Destructive

AbstractX-ray diffraction methods for studying solid-state diffusion are reviewed. Because of the lack of penetration, such methods are suited for diffusion zones spanning only a few microns. Most involve analyses of one, or more, (hkl) “band” of intensities spread in 2θ as a result of the corresponding lattice parameter spread associated with compositional inhomogeneities. Further, many are non-destructive, making it possible to follow the progression of diffusion with time in the same specimen.

Crystal Structures of New Compounds Na0.5Sm4.5Ti4O15 and Na0.5Eu4.5Ti4O15

2011 ◽  
Vol 415-417 ◽  
pp. 468-471
Author(s):  
Qiao Hong Yu ◽  
Zheng Fa Li ◽  
Yong Xiang Li ◽  
Ping Zhan Si ◽  
Jiang Ying Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordinary Temperature ◽  
Europium Titanate ◽  
New Compounds

New compounds of sodium samarium titanate Na0.5Sm4.5Ti4O15and sodium europium titanate Na0.5Eu4.5Ti4O15were synthesized successfully by solid state reaction at 1300 oC and 1200 oC, respectively. The lattice parameters of Na0.5Sm4.5Ti4O15and Na0.5Eu4.5Ti4O15were determined at ordinary temperature by using X-ray powder diffraction method. Their Lattice types were determined, and their patterns were indexed. Polycrystalline X-ray diffraction data of sodium samarium titanate were listed. Differences of their crystal structures were analyzed and discussed.

Powder X-Ray Data for Synthetic Anhydrous Sodium Zirconium Silicates

1987 ◽  
Vol 2 (3) ◽  
pp. 176-179 ◽  
Author(s):  
G. Wilson ◽  
F. P. Glasser
Keyword(s):  
Solid State ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
The Other ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Sodium Zirconium ◽  
Diffraction Patterns

AbstractA systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.

Thermodynamic Analysis of the Extension of Solid Solubility of the Cu-Cr System Processed by Mechanical Alloying

2011 ◽  
Vol 311-313 ◽  
pp. 392-395 ◽  
Author(s):  
Kun Yu Shi ◽  
Tao Shen ◽  
Li Hong Xue ◽  
Chun Hao Chen ◽  
You Wei Yan
Keyword(s):  
Mechanical Alloying ◽  
Thermodynamic Analysis ◽  
Solid Solubility ◽  
Structural Changes ◽  
Milling Time ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cr System

The nanocrystalline Cu-5wt.%Cr alloy powders were prepared by mechanical alloying. The structural changes were characterized by X-ray diffraction (XRD) technique. A thermodynamic analysis was carried out to predict the change in the solubility limit of this system. It was found that the energy resulting from the MA process is sufficient to increase the solid solubility of immiscible Cr-Cu system. The solid solubility may be extended up to 5 wt.% Cr in Cu after 20 h milling. The formation of the supersaturated solid solution leads to the decrease of Cu lattice parameter. However, it decomposes with the further increase of the milling time, which leads to the increase of Cu lattice parameter.

Characterization of the Aurivillius Type PbBi4Ti4O15 Piezoelectric Ceramic Doped with Eu3+

2006 ◽  
Vol 45 ◽  
pp. 2483-2488
Author(s):  
L. Pablos ◽  
Maria Elena Villafuerte-Castrejón ◽  
A. Ibarra-Palos ◽  
J. Ocotlán-Flores ◽  
R. Sato ◽  
...  
Keyword(s):  
Piezoelectric Ceramic ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Layered Oxides ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Density Measurements ◽  
X Ray ◽  
Wide Range

PbBi4Ti4O15 belongs to the bismuth oxide layers family discovered by Aurivillius more than 50 years ago. In the last few years, there has been considerable interest in layered oxides exhibiting ferroelectric, piezoelectric and other related properties due to their wide range of application in technical devices. In the present work the PbBi4Ti4O15 solid solution formed with Eu3+ was synthesized by coprecipitation method and solubility limit was found. All compounds were characterized by scanning electron microscopy, density measurements and X-ray diffraction. The variation of lattice parameter with the Eu3+ concentration was obtained. Raman spectroscopy was carried out in order to determine the Eu3+ site in the lattice. Thermal analysis (thermogravimetry and differencial scanning calorimetry) results are also presented.

Use of X-Ray Diffraction as an Analytical Technique for the Synthesis of Inorganic Catalysts

1987 ◽  
Vol 2 (3) ◽  
pp. 183-186
Author(s):  
G. I. Straguzzi ◽  
Paden F. Dismore
Keyword(s):  
Solid State ◽  
Qualitative Analysis ◽  
Surface Area ◽  
Selective Oxidation ◽  
Powder Diffraction ◽  
Minimum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analytical Technique ◽  
Selective Oxidation Catalysts

AbstractX-ray powder diffraction was used as an analytical technique for the solid state synthesis of selective oxidation catalysts with large surface area. Qualitative analysis was used to determine the minimum temperature at which the synthesis was complete. Quantitative diffraction was used to analyze mixtures of isomorphous antimonates. Results indicated that the final mixtures are independent of the method of preparation, i.e., mixing or impregnation.

A Sample Holder for X-Ray Powder Diffraction Studies of Flakiness and Block Sample

2013 ◽  
Vol 544 ◽  
pp. 433-436
Author(s):  
Hua Yong Zhang ◽  
Xiao Jian Liu ◽  
Hai Yan Sun ◽  
Chun Sheng Fan
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Low Cost ◽  
Sample Holder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Block Sample ◽  
Powder Diffractometer ◽  
Analytical Results ◽  
Sample Carrier

Powder X-ray diffraction (XRD) is one of the primary techniques used to characterize solid state materials. But there is not a sample holder which can be fit into the sample carrier of the Bruker D8-Advance x-ray powder diffractometer for flakiness and block samples test. In this article, we will design, manufacture and evaluate a sample holder for flakiness and block samples. Materials of the holder are steel, glass and plasticine etc. The holder is low cost, easy to be processed, convenience to prepare the samples, and accurately obtain the best analytical results.

Lattice parameters and spontaneous strain in AX 2 polytypes: CdI2, PbI2 SnS2 and SnSe2

1989 ◽  
Vol 22 (6) ◽  
pp. 622-623 ◽  
Author(s):  
B. Pałosz ◽  
E. Salje
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Basal Plane ◽  
Lattice Parameter ◽  
Structural Transformations ◽  
Lattice Parameters ◽  
The Other ◽  
X Ray Diffraction ◽  
Spontaneous Strain ◽  
X Ray

Structural transformations between polytypes of a given material are expected to lead to lattice relaxations. Powder X-ray diffraction of basic AX 2 polytypes of CdI2, PbI2, SnS2 and SnSe2 showed these relaxations for the repetition unit along the stacking axis, conventionally the c axis. No variation of the lattice parameters were detected in the basal plane (001), except for CdI2 where small variations occur also for the a lattice parameter. The tensor of the spontaneous strain has its maximum component e 3 ≲ 12 × 10−4 for SnS2. The powder diffraction pattern and lattice parameters of the phases of CdI2 (2H, 12R, 4H), PbI2 (2H, 12R), SnS2 (2H, 18R, 4H) and SnSe2 (2H, 18R) are given. JCPDS Diffraction File Nos. are: 40-1468 for CdI2-12H; 40–1469 for CdI2-2H; 40-1466 for SnS2-18R, 40–1467 for SnS2-2H; 40–1465 for SnSe2-18R. The other polytypes studied in this paper have data in earlier sets of the PDF.

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