Determination of microstructural characteristics of tungsten nanopowders from the profile of a single diffraction peak using WinFit software

2015 ◽  
Vol 51 (15) ◽  
pp. 1452-1456
Author(s):  
V. P. Sirotinkin ◽  
A. B. Mikhailova ◽  
V. F. Shamrai ◽  
A. V. Samokhin ◽  
M. A. Sinaiskii ◽  
...  
Keyword(s):  
Diffraction Peak ◽  
Microstructural Characteristics ◽  
Single Diffraction

MAGNETIC PROPERTIES OF ONE-DIMENSIONAL Sm-DOPED ZnO NANOSTRUCTURES FABRICATED BY HYDROTHERMAL METHOD

2013 ◽  
Vol 27 (22) ◽  
pp. 1350161 ◽  
Author(s):  
C. C. LIN ◽  
C. Y. KUNG ◽  
S. L. YOUNG ◽  
H. Z. CHEN ◽  
M. C. KAO ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Zno Nanorods ◽  
Magnetization Measurement ◽  
Hexagonal Structure ◽  
Diffraction Peak ◽  
Zno Nanostructures ◽  
One Dimensional ◽  
Doped Zno ◽  
Single Diffraction ◽  
Xrd Patterns

Well-defined ZnO and Sm -doped nanorods have been successfully fabricated by a low temperature hyderthermal process. The XRD patterns of both compositions with single diffraction peak (002) show the same wurtzite hexagonal structure. The radius of Sm - ZnO nanorods observed by FE-SEM is smaller than that of pure ZnO indicating the reduction of growth rate by the doping of Sm . Ferromagnetism is observed from the results of magnetization measurement. The increase of the saturation magnetization and decrease of coercivity reveal an association with the increase of oxygen vacancies induced by the doping of the Sm in the nanorods.

scholarly journals Precision X-Ray Stress Analysis of Uranium and Zirconium

1959 ◽  
Vol 3 ◽  
pp. 331-336
Author(s):  
B. J. Wooden ◽  
Lt. E. C. House ◽  
R. E. Ogilvie
Keyword(s):  
Residual Stresses ◽  
Stress Analysis ◽  
Peak Position ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Least Squares Fit ◽  
Order Polynomial ◽  
Desk Calculator

AbstractThe feasibility of using X-ray diffraction methods to measure residual stresses in uranium and zirconium (Zircaloy-2) was investigated. A precision method was developed for the determination of diffraction peak positions and the precision associated therewith. The statistical tables of Fisher and Yates were used to determine what order polynomial provided the best least squares fit within the known precision of the observed data. It was found that a second-order polynomial provided an adequate regression. With the aid of a desk calculator less than 5 min calculation time is required to determine the peak position to a precision of ±0.01°.The stress constant for uranium was determined to be 1308 ± 110 psi/0.01° shift in Δ2θ for copper radiation on the (116) planes at 2θ = 158.3°. The stress constant for Zircaloy-2 was determined to be 430 ± 1 psi/0.01° shift in Δ2θ for chromium radiation on the (10,4) planes at 2θ = 156.4°.

Space-group determination from powder diffraction data: a probabilistic approach

2004 ◽  
Vol 37 (6) ◽  
pp. 957-966 ◽  
Author(s):  
Angela Altomare ◽  
Rocco Caliandro ◽  
Mercedes Camalli ◽  
Corrado Cuocci ◽  
Iván da Silva ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Probabilistic Approach ◽  
Group Symmetry ◽  
Large Set ◽  
Powder Diffraction Data ◽  
Space Group ◽  
Lattice Symmetry ◽  
Quantitative Basis ◽  
Single Diffraction

Experimental powder diffraction diagrams, once indexed and decomposed into single diffraction intensities, can be submitted to statistical analysis for the determination of space-group symmetry. A new algorithm is illustrated, which is able to provide, on a quantitative basis, a probability value for each extinction symbol compatible with the previously established lattice symmetry. The algorithm has been implemented inEXPO2004[Altomare, Caliandro, Camalli, Cuocci, Giacovazzo, Moliterni & Rizzi (2004).J. Appl. Cryst.37, 1025–1028] and has been successfully tested using a large set of experimental data.

Engineering properties and microstructural characteristics of cement-stabilized zinc-contaminated kaolin

2014 ◽  
Vol 51 (3) ◽  
pp. 289-302 ◽  
Author(s):  
Yan-Jun Du ◽  
Ning-Jun Jiang ◽  
Song-Yu Liu ◽  
Fei Jin ◽  
Devendra Narain Singh ◽  
...  
Keyword(s):  
Engineering Properties ◽  
Kaolin Clay ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Microstructural Characteristics ◽  
Theoretical Simulation ◽  
Zn Concentration ◽  
Cement Additive ◽  
Diameter Change

This paper presents details of a study that deals with determination of engineering properties, identification of phases of major hydration products, and microstructural characteristics of a zinc-contaminated (referred to as Zn-contaminated in this paper) kaolin clay when it is stabilized by a cement additive. Investigations were carried out with respect to the effect of the level of zinc (Zn) concentration on the overall soil properties including Atterberg limits, water content, pH, stress–strain characteristics, unconfined compressive strength, and secant modulus. In addition, X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry studies were conducted to understand the mechanisms controlling the changes in engineering properties of the stabilized kaolin clay. The study reveals that the level of Zn concentration has a considerable influence on the engineering properties, phases of hydration products formed, and microstructural characteristics of the stabilized kaolin clay. These changes are attributed to the retardant effect of Zn on the hydration and pozzolanic reactions, which in turn alters the phases of hydration products and cementation structure – bonding of the soils. Theoretical simulation of the pore-size distribution curves demonstrates that the cement-stabilized kaolin exhibits bimodal type when the Zn concentration is less than 2%, whereas it displays unimodal type when the Zn concentration is 2%. With an increase in the Zn concentration, the characteristics of the interaggregate pores in terms of volume and mean diameter change considerably, whereas those of intra-aggregate pores remain nearly unchanged.

Microstructures of Ni/Cu and Ni-Co/Cu Multilayers Produced by Electrodeposition Method

2007 ◽  
Vol 26-28 ◽  
pp. 1321-1324 ◽  
Author(s):  
Yoshihisa Kaneko ◽  
T. Sanda ◽  
Satoshi Hashimoto
Keyword(s):  
Diffraction Analysis ◽  
Vickers Hardness ◽  
Electric Potential ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Electrodeposition Technique ◽  
Multilayered Structures ◽  
X Ray ◽  
Single Diffraction ◽  
Two Peaks

Microstructures of Ni/Cu and Ni-Co/Cu multilayers were investigated by X-ray diffraction analysis. These multilayered structures were fabricated on copper substrates using electrodeposition technique. At an as-deposited Ni/Cu multilayer with the layer thickness of h=5nm, a single diffraction peak appeared, although the multilayer of h=100nm exhibited the diffractions splitting into two peaks which resulted from both the Ni and Cu layers. In the Ni-Co/Cu multilayers, it was found that composition of the Ni-Co layer depended on an electric potential applied during deposition. The fcc and hcp structures were detected at the Ni-rich and the Co-rich deposits, respectively. The Vickers hardness of the Co-Ni/Cu multilayer was higher than that of the Ni/Cu multilayer.

scholarly journals MWP-fit: a program for multiple whole-profile fitting of diffraction peak profiles byabinitiotheoretical functions

2001 ◽  
Vol 34 (5) ◽  
pp. 669-676 ◽  
Author(s):  
G. Ribárik ◽  
T. Ungár ◽  
J. Gubicza
Keyword(s):  
Size Distribution ◽  
Fourier Transforms ◽  
Diffraction Peak ◽  
Hexagonal Crystal ◽  
Crystal Lattices ◽  
Microstructural Parameters ◽  
Fitting Procedure ◽  
Profile Fitting ◽  
Log Normal

A computer program has been developed for the determination of microstructural parameters from diffraction profiles of materials with cubic or hexagonal crystal lattices. The measured profiles or their Fourier transforms are fitted byabinitiotheoretical functions for size and strain broadening. In the calculation of the theoretical functions, it is assumed that the crystallites have log-normal size distribution and that the strain is caused by dislocations. Strain and size anisotropy are taken into account by the dislocation contrast factors and the ellipticity of the crystallites. The fitting procedure provides the median and the variance of the size distribution and the ellipticity of the crystallites, and the density and arrangement of the dislocations. The efficiency of the program is illustrated by examples of severely deformed copper and ball-milled lead sulfide specimens.

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