XRD Study of the Nacrite/CsCl/H2O Intercalation Complex

2004 ◽  
Vol 443-444 ◽  
pp. 59-64 ◽  
Author(s):  
S. Naamen ◽  
H. Ben Rhaiem ◽  
A. Ben Haj Amara
Keyword(s):  
Direct Method ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
Intercalation Complex ◽  
Xrd Pattern ◽  
X Ray ◽  
Caesium Chloride ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
A Direct Method

The intercalation complex of nacrite with an alkali halide (Caesium chloride: CsCl) has been successfully prepared by mixing a CsCl saturated solution with a 8.4Å-hydrated nacrite. The homogeneous nacrite/CsCl complex has been studied by X-ray diffraction (XRD). Using an oriented clay aggregate, 10 basal reflections were obtained. The XRD pattern showed basal spacing of 10.5Å with integral series of 00l reflections indicating an ordered stacking of parallel 1:1 layers. A direct method involving a monodimensional electron density projection, along the normal to the layers, is used to determine the number and the position of intercalated compounds. The best agreement between observed and simulated p(Z) (R = 5%) is obtained by placing one Cl- ion at Z=6.7Å; one Cs+ ion at Z=8.3Å and two H O molecules at 6.3 and 7.4Å.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

Swelling behavior of montmorillonite cation exchanged for ω-amino acids by ∊-caprolactam

1993 ◽  
Vol 8 (5) ◽  
pp. 1174-1178 ◽  
Author(s):  
Arimitsu Usuki ◽  
Masaya Kawasumi ◽  
Yoshitsugu Kojima ◽  
Akane Okada ◽  
Toshio Kurauchi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Room Temperature ◽  
Carbon Number ◽  
Nylon 6 ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Silicate Layers

Natural Na-montmorillonite was cation exchanged for the ammonium cations of various ω-amino acids [H3N+(CH2)n−1 COOH, n = 2, 3, 4, 5, 6, 8, 11, 12, and 18]. X-ray diffraction (XRD) results suggested that the chain axes of ω-amino acids with a carbon number of eight or less were parallel to the silicate layers, and that the chain axes of those with a carbon number of 11 or more were slanted to the layers. The cation-exchanged montmorillonites form intercalated compounds with ∊-caprolactam at 25 °C. The montmorillonites intercalated with both ω-amino acid and ∊-caprolactam were studied by XRD measurement at room temperature and 100 °C. We propose a model where amino acid molecules were arranged perpendicular to silicate layers and ∊-caprolactam molecules filled the space between them. When the ∊-caprolactam was melted at 100 °C, the basal spacing for the montmorillonite increased, in which the carbon number exceeds 11. This phenomenon will be applicable to obtaining the nylon 6-clay hybrid, a molecular composite of nylon 6 and montmorillonite.

Determination of depth profiles from X-ray diffraction data

1993 ◽  
Vol 8 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Paul Predecki
Keyword(s):  
Diffraction Data ◽  
Direct Method ◽  
Sample Surface ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
Depth Profiles ◽  
A Direct Method

A direct method is described for determining depth profiles (z-profiles) of diffraction data from experimentally determined τ-profiles, where z is the depth beneath the sample surface and τ is the 1/e penetration depth of the X-ray beam. With certain assumptions, the relation between these two profile functions can be expressed in the form of a Laplace transform. The criteria for fitting experimental τ-data to functions which can be utilized by the method are described. The method was applied to two τ-data sets taken from the literature: (1) of residual strain in an A1 thin film and (2) of residual stress in a surface ground A12O3/5vol% TiC composite. For each data set, it was found that the z-profiles obtained were of two types: oscillatory and nonoscillatory. The nonoscillatory profiles appeared to be qualitatively consistent for a given data set. The oscillatory profiles were considered to be not physically realistic. For the data sets considered, the nonoscillatory z-profiles were found to lie consistently above the corresponding τ-profiles, and to approach the τ-profiles at large z, as expected from the relation between the two.

Proposed Methods for Depth Profiling of Residual Stresses using Grazing Incidence X-Ray Diffraction (GIXD)

1992 ◽  
Vol 36 ◽  
pp. 237-245 ◽  
Author(s):  
Paul Predecki ◽  
X. Zhu ◽  
B. Ballard
Keyword(s):  
Integral Method ◽  
Direct Method ◽  
Incident Angle ◽  
Strain Tensor ◽  
Depth Profiling ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
A Direct Method

AbstractTwo proposed methods are described for obtaining the depth profiles (τ-profiles) of strains and stresses as a function of the 1/e penetration depth τ, using GIXD in the asymmetric geometry, without the need for layer removal. In the first, the ψ-method: ψ is varied, for a given reflection, while holding τ constant, by varying the wavelength λ and adjusting the incident angle α so as to maintain τ constant. This allows dϕ,ψ vs Sin2ψ plots to be obtained at constant τ. In the second, the ϕ-integral method: interplanar spacings dϕ,ψ are measured for ϕ values from 0 to 2π, at constant ψ and τ by holding α fixed. Two ψ values, i.e. two wavelengths, are needed to obtain the whole strain tensor, but if the sample is quasi-isotropic and the stress state is biaxial, only one wavelength is needed. A direct method is also described for obtaining the profiles as a function of depth z (z-profiles) from the corresponding τ-profiles using inverse Laplace transforms. Application of the method to the residual strain vs τ data of Doerner and Brennan for an Al film on Si is presented.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

scholarly journals Direct mapping of fiber diffraction patterns into reciprocal space

2009 ◽  
Vol 42 (2) ◽  
pp. 295-301 ◽  
Author(s):  
Norbert Stribeck ◽  
Ulrich Nöchel
Keyword(s):  
Direct Method ◽  
Reciprocal Space ◽  
Polymer Materials ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Direct Mapping ◽  
Fiber Diffraction ◽  
Mapping Parameters ◽  
Diffraction Patterns ◽  
A Direct Method

On the basis of the concept of Polanyi [Z. Phys.(1921),7, 149–180], the mapping of fiber diffraction patterns into reciprocal space is revisited. The result is a set of concise mapping relations that does not contain any approximations. This set permits the design of a direct method that, in principle, does not require refinement of mapping parameters even for patterns of tilted fibers. The method is unsuitable for diffuse scattering patterns. If inaccuracies of two pixels can be tolerated, a pattern is automatically mapped into reciprocal space in real time. The method is proposed for the processing of the extensive sets of patterns that are recorded in time-resolved wide-angle X-ray diffraction investigations of polymer materials.

scholarly journals Isoterma dan Termodinamika Adsorpsi Kation Cu2+ Fasa Berair pada Lempung Cengar Terpilar

2012 ◽  
Vol 14 (1) ◽  
pp. 7
Author(s):  
Syaiful Bahri ◽  
Muhdarina Muhdarina ◽  
Nurhayati Nurhayati ◽  
Fitri Andiyani
Keyword(s):  
Gibbs Energy ◽  
Sodium Acetate ◽  
Atmospheric Condition ◽  
Freundlich Isotherm ◽  
Pillared Clays ◽  
Basal Spacing ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Clay Suspension ◽  
X Ray

Pillared Cengar clay have been synthesized by two methods, first clay suspension is directly mixed into aqueous solution of hydroxy-aluminum polycations (WK) and second by mixing the clay suspension into the solution of sodium acetate and hydroxy-aluminumpolycations (SAK) sequentially. Both clays were calcined in air on atmospheric condition. Diffraction pola, surface morphology and cationexchange capacity of the pillared clays were characterized using X Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) andvisible spectrophotometry methods, respectively. The pillared clays showed increases of basal spacing from 3.57 Å to 4.55 Å and smectiteas a new mineral. Morphology of SAK has more heterogeneous surface with small plates and agglomeration of grains compare with WKwhich small plates. Adsorption of aqueous cation of Cu 2+ were studied on various variables of initial concentration as well as temperatures.As the result, adsorption of cation Cu 2+ on pillared Cengar clay is corresponding to Freundlich isotherm, while the adsorption capacity ofWK on cation Cu 2+ is slightly lower than SAK. The thermodynamic aspect, the WK is reflected possessed exothermic processes withnegative entropy, increased in Gibbs energy and non spontaneous, while the SAK possessed endothermic processes having positive entropy,decreased in Gibbs energy and non spontaneous.

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