X-ray peak profile analysis of dislocation type, density and crystallite size distribution in cold deformed Pb-Ca-Sn alloys

Abouhilou, F.; Khereddine, Abdel Yazid; Alili, B.; Bradai, Djamel

doi:10.1016/s1003-6326(11)61220-x

Cited by 13 publications

(4 citation statements)

References 14 publications

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“…The homogeneous contrast factor approach has been widely used to quantify cubic alloys. Including, the amount of edge or screw dislocations [24][25][26][27][28], or the relative quantities of different slip types [29] in cubic crystals.…”

Section: Cubic Alloysmentioning

confidence: 99%

Peak Broadening Anisotropy and the Contrast Factor in Metal Alloys

Simm

2018

Crystals

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Diffraction peak profile analysis (DPPA) is a valuable method to understand the microstructure and defects present in a crystalline material. Peak broadening anisotropy, where broadening of a diffraction peak doesn't change smoothly with 2θ or d-spacing, is an important aspect of these methods. There are numerous approaches to take to deal with this anisotropy in metal alloys, which can be used to gain information about the dislocation types present in a sample and the amount of planar faults. However, there are problems in determining which method to use and the potential errors that can result. This is particularly the case for hexagonal close packed (HCP) alloys. There is though a distinct advantage of broadening anisotropy in that it provides a unique and potentially valuable way to develop crystal plasticity and work-hardening models. In this work we use several practical examples of the use of DPPA to highlight the issues of broadening anisotropy. of 31where, D is the crystal size, K Sch is the Scherrer constant (often taken as 0.9 for spherical crystals), g is the reciprocal of the d-spacing of a peak, f m is a function related to the arrangement of dislocations (and represents how the arrangement of groups of dislocations influence their total strain), ρ is the dislocation density and C hkl is the average contrast factor of dislocations in grains that contribute to the hkl diffraction peak. In Equation 1 and other DPPA approaches, C hkl is assumed to be the only term that accounts for broadening anisotropy and its value is required to be able to obtain the dislocation density.TEM to be able to identify details of dislocations [15,16], especially in cases when g.b=0 does not lead to vanishing contrast or due to practicalities of rotating a sample. In the same manner, the diffraction broadening caused by a dislocation varies depending on the diffraction vector, and can be calculated by modelling the dislocation's displacement field. The contribution of a dislocation's displacement field to the broadening of different diffraction profiles is through what is known as the contrast (or orientation) factor of dislocations. The contrast factor of an individual dislocation is dependent on the angles between the diffraction vector and the vectors that define the dislocation: it's Burgers vector (b), slip plane normal (n), and dislocation line (s). The contrast factor of an individual dislocation can be calculated using the computer program ANIZC [17]. For example, the edge dislocation in Figure 2 has a contrast factor of 0.46 when g is [110] and parallel to the dislocations Burgers vector. The value is 0.00 when g is parallel to the slip line ([11 2]) and 0.05 when g is parallel to the slip plane normal ([1 11]).

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Section: Cubic Alloysmentioning

confidence: 99%

Peak Broadening Anisotropy and the Contrast Factor in Metal Alloys

Simm

2018

Crystals

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“…X-ray diffraction line profile analysis (XRDLPA) was used to study the microstructure of the prepared samples. The line broadening is a result of the small size of the crystalline [15][16][17][18] as well as the non-uniform displacements strain of the atoms with respect to their reference lattice positions [18] . The observed integral breadth of the sample is a convolution of an instrument and a physical factor.…”

Section: Microstructural Characterizationmentioning

confidence: 99%

Microstructural and Electrical Properties of (WO3)1-x(MoO3)x Thin Films Synthesized by Spray Pyrolysis Technique

Aa¹,

Sa²,

Ma³

2017

Res. Rev. J Mat. Sci

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INTRODUCTIONTransition metal oxides have been widely used as gas-sensing, opto-electronic devices and inorganic electrochromic materials [1] . Tungsten trioxide (WO 3 ) and molybdenum oxide (MoO 3 ) thin film are one of the most promising material in Electrochromic and gas-sensing studies, and a common gasochromic window because their sensitivity to various gases, such as NO, NO 2 , CO, NH 3 and H 2 , which is due to the physical and chemical properties of these oxides [2][3][4] . The reason for choosing WO 3 as a doping with MoO 3 is because its film has a high transparency, high electrochemical activity and stability. The interaction between WO 3 and MoO 3 is unique due to their similar ionic radii and nearly-identical structures in their highest oxidation state. In addition, they were used in the electrochromic process as a cathode material due to the following reasons, they are (i) high specific energy density [5] , (ii) undergo reversible potactic reaction with ions [6] and (iii) they have a higher electrochemical activity with the highest stability. In order to improve the quality of sensitivity of gas detection, the variation of gas-sensing and electrochromic devices, the binary combinations of oxides will modify and improve the characteristic of different oxides.Composite trioxides of (WO 3 ) 1-x (MoO 3 ) x films have been prepared by different techniques; such as the vacuum evaporation [7,8] , electro-deposition [9,10] , sputtering [11] , electron-beam deposition [12] and sol-gel deposition [13,14] . The spray pyrolysis process offers several advantages over conventional deposition techniques for the control of stoichiometry and film structure.This work is aimed to present mixed metal oxide sprayed synthesis of new molybdenum trioxide doped tungsten trioxide film, WO 3 -MoO 3 and study the microstructral and electrical characteristics. The extent of a mixture concentration of MoO 3 ranges from 10-40 mol% in this study. A detailed structural characterization of the WO 3 -MoO 3 thin films was presented by X-ray diffraction (XRD) and as well as the study of the electrical properties was done. Also they have been studying the influence of thermal annealing on the properties of different concentrations. Structural and electrical properties correlation was aimed to study. EXPERIMENTAL WORK Samples PreparationMolybdenum trioxide doped tungsten trioxide films were prepared using a chemical spray pyrolysis technique. The precursor solutions were prepared by dissolving ammonium paratungstate and ammonium paramolybdate with a solution molarity of 0.005 M in a hot distilled water of 333K. The molybdenum trioxide concentration is coincident with the percentage in atomic weight of ammonium paramolybdate dissolved in the sprayed solution. Different atomic percentages quantities, namely 10, 20, 30 and ABSTRACT New composite oxides of (WO 3 ) 1-x (MoO 3 ) x thin films were deposited by spray pyrolysis method. Microstructural and electrical properties of the films as-deposited and after annealing at different MoO 3 conce...

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“…Comparing data on the calculated and measured parameter q, one can estimate the number of screw and edge dislocation (see [26,27]). Now, if to construct the experimental dependence y = [(DK) 2 À (0.9/r) 2 ]/K 2 (under certain r), we should get a straight line y = A + B[.…”

Section: Discussionmentioning

confidence: 99%