Topic
Le Bail method
About: Le Bail method is a research topic. Over the lifetime, 37 publications have been published within this topic receiving 371 citations.
Papers
TL;DR: In this article, a polypyrrole powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X-ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM).
Abstract: Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X-ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1)%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a = 7.1499 (2) A, b = 13.9470 (2) A, c = 17.3316 (2) A, α = 90 A, β = 61.5640 (2) A and γ = 90 A) were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT) and suggests that tetramer polymer chains are arranged along the "c" direction. Average crystallite size was found in the range of 20 (1) A. A value of 9.33 × 10-9 S/cm was found for PPY conductivity.
81 citations
TL;DR: From activation energy estimation and dielectric loss analysis, thermally activated process related to the mobility of oxygen ion vacancy was found responsible for the observed ionic conductivity and a similar conclusion was reached after careful analysis of dielectrics spectroscopy data of this sample.
Abstract: Equimolar concentrations of Zr4+ and Bi3+ were chelated with ethylenediaminetetraacetic acid ligand with the purpose of using it as a precursor to generate pyrochlore-like Bi2Zr2O7. When the X-ray amorphous precursor was calcined at 750 °C for 3 h in air, pyrochlore-like product with superstructure reflections was identified by powder X-ray diffraction (PXRD) along with one minor reflection due to β-Bi2O3. This phase was found to be metastable from additional experiments conducted by varying calcination conditions. Structural refinement of PXRD pattern by Le Bail method in Fd3m space group yielded cubic lattice constant of 10.8421(27) A. Flower-petal-like morphology of the sample was evident in its field-emission scanning electron microscopy image and energy-dispersive X-ray analysis performed at various locations of the specimen confirmed nearly equal concentration of zirconium and bismuth. Six bands at 260, 320, 448, 531, 597, and 828 cm–1 were observed for this sample in its Raman spectrum and support...
51 citations
TL;DR: In this paper, the crystal structures of two new zinc compounds of propylenebis(phosphonic acid) were determined ab initio from their powder diffraction data, which were prepared by the reaction of zinc chloride with the phosphonic acid at different pH conditions.
Abstract: The crystal structures of two new zinc compounds of propylenebis(phosphonic acid) were determined ab initio from their powder diffraction data. These compounds were prepared by the reaction of zinc chloride with the phosphonic acid at different pH conditions. The compound, Zn(HO3PC3H6PO3H) (1), crystallizes in the monoclinic space group P21/n with a = 18.167(3) A, b = 5.083(1) A, c = 8.658(1) A, β = 93.630(2)° and Z = 4. The other compound, Zn3[(HO3PC3H6PO3)2]·2H2O (2), also crystallizes in the monoclinic symmetry but with space group C2/c. Crystal data: a = 20.5853(4) A, b = 5.0472(1) A, c = 18.0140(4) A, b = 97.226(1)°, Z = 4. The intensities of the structure factors were extracted from the powder patterns using the Le Bail method and were used for structure solution by direct methods. The structures were then completed by Fourier methods and refined by Rietveld methods. In structure 1, the metal atoms are tetrahedrally coordinated by four oxygen atoms, two each from two independent phosphonates. The r...
44 citations
TL;DR: In this paper, the measurement of lattice parameters using the Le Bail method was shown to be inappropriate for a complex, low symmetry, structure, even with high resolution synchrotron diffraction data.
Abstract: The measurement of lattice parameters using the Le Bail method was shown to be inappropriate for a complex, low symmetry, structure, even with high resolution synchrotron diffraction data. The method failed as a result of ambiguous indexing in the absence of constraints on diffraction intensities, that arise when a structural model is used, combined with the large number of reflections. A caution for the use of the Le Bail and other whole-powder pattern decomposition methods is presented, particularly for high reflection density data.
43 citations
TL;DR: In this paper, a neutralization of polyaniline emerine-base form (EB-PANI) using NaOH 0.5 M at 3, 24 and 48h of neutralization was described.
42 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 6 |
| 2019 | 3 |
| 2018 | 3 |
| 2017 | 4 |
| 2015 | 2 |