Investigating Interdiffusion in Mo/V Multilayers from X-Ray Scattering and Kinetic Simulations

In order to investigate interdiffusion in Mo/V multilayers, we present a method that combines both kinetic mean-field simulations and calculations of x-ray scattered intensity with disorder effects. Considering preliminary experimental data obtained on Mo(4nm)/V(2nm) multilayers, we show that the angular shift of spectra observed after annealing, should take place for both Fickian and asymmetric interdiffusion modes. In contrast, clear signatures of the interdiffusion modes are found from the simulation of the peak intensities. These results offer interesting perspectives for a full analysis of the interdiffusion in these systems.

Download Full-text

Determination of nanostructure of liposomes containing two model drugs by X-ray scattering from a synchrotron source

Journal of Synchrotron Radiation ◽

10.1107/s0909049513020074 ◽

2013 ◽

Vol 20 (5) ◽

pp. 721-728 ◽

Cited By ~ 8

Author(s):

Alexandr Nasedkin ◽

Jan Davidsson ◽

Mont Kumpugdee-Vollrath

Keyword(s):

Experimental Data ◽

Small Angle ◽

Structural Parameters ◽

Water Layer ◽

Synchrotron Source ◽

X Ray ◽

X Ray Scattering ◽

Extract Information ◽

Ray Scattering

Small-angle X-ray scattering has been employed to study how the introduction of paracetamol and acetylsalicylic acid into a liposome bilayer system affects the system's nanostructure. An X-ray scattering model, developed for multilamellar liposome systems [Pabstet al.(2000),Phys. Rev. E,62, 4000–4009], has been used to fit the experimental data and to extract information on how structural parameters, such as the number and thickness of the bilayers of the liposomes, thickness of the water layer in between the bilayers, size and volume of the head and tail groups, are affected by the drugs and their concentration. Even though the experimental data reveal a complicated picture of the drug–bilayer interaction, they clearly show a correlation between nanostructure, drug and concentration in some aspects. The localization of the drugs in the bilayers is discussed.

Download Full-text

Diffuse X-ray scattering and order-disorder effects in the iodide chain compounds N,N′-diethyl-N,N′-dihydrophenazinium iodide, E2PI1.6, and N,N′-diebenzyl-N,N′-dihydrophenazinium iodide, B2PI1.6

Journal of Physics and Chemistry of Solids ◽

10.1016/0022-3697(82)90239-6 ◽

1982 ◽

Vol 43 (8) ◽

pp. 739-748 ◽

Cited By ~ 11

Author(s):

H. Endres ◽

J.P. Pouget ◽

R. Comes

Keyword(s):

X Ray ◽

Disorder Effects ◽

X Ray Scattering ◽

Chain Compounds ◽

Ray Scattering

Download Full-text

Simulation of small-angle X-ray scattering from thylakoid membranes

Journal of Applied Crystallography ◽

10.1107/s0021889809017701 ◽

2009 ◽

Vol 42 (4) ◽

pp. 649-659 ◽

Cited By ~ 10

Author(s):

J. J. K. Kirkensgaard ◽

J. K. Holm ◽

J. K. Larsen ◽

D. Posselt

Keyword(s):

Experimental Data ◽

Small Angle ◽

Virtual Instrument ◽

Three Dimensional ◽

Thylakoid Membranes ◽

Three Dimensional Model ◽

General Applicability ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

Small-angle X-ray scattering (SAXS) patterns are calculated from a three-dimensional model of photosynthetic thylakoid membranes. The intricate structure of the thylakoids is represented by sampling random `electron density points' on geometric surfaces. The simulation setup works as a virtual instrument, allowing direct comparison with experimental data. The simulations qualitatively reproduce experimental data and thus clarify the structural origin of the scattering features. This is used to explain recent SAXS measurements and as a guideline for new experiments and future quantitative modeling. The setup has general applicability for model testing purposes when modeling scattering from membrane systems of complex geometries.

Download Full-text

SWING detection vacuum tunnel

Diamond Light Source Proceedings ◽

10.1017/s2044820111000189 ◽

2011 ◽

Vol 1 (MEDSI-6) ◽

Author(s):

D. Dalle ◽

J. Perez ◽

O. Lyon ◽

P. Feret ◽

C. Menneglier ◽

...

Keyword(s):

Small Angle ◽

Vacuum Chamber ◽

Incident Beam ◽

Angular Range ◽

Scattered Intensity ◽

Long Distance ◽

General Design ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

The SWING beamline is dedicated to the study of the small-angle X-ray scattering. In order to have the possibility to detect scattered intensity very close to the incident beam, it is absolutely necessary to install the detector at a long distance from the sample. In addition, it is easy to change the detector's position to access a wider angular range. A long and large vacuum chamber, the ‘tunnel’, has been designed with specific mechanisms inside to control the detector's position with micrometre resolution. Special attention has been given so as to offer a very useful device to the users. The paper will present the general design of the tunnel equipped with ancillary devices such as very narrow and stiff beam stoppers, diode holders and beam attenuators.

Download Full-text

Measuring the specific surface area of mesoporous silica using x-ray scattering

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314094005 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C599-C599

Author(s):

Julien Cambedouzou ◽

Olivier Diat

Keyword(s):

Experimental Data ◽

Specific Surface ◽

Surface Area ◽

Mesoporous Materials ◽

Specific Surface Area ◽

Small Angle ◽

X Ray ◽

X Ray Scattering ◽

Mcm 41 ◽

Ray Scattering

The development of porous silica or carbon material with high specific surface area raises a high interest in the field of materials science given their potential interest in a wide range of applications including catalysis, water treatment or drug delivery. Among these mesoporous structures, those consisting of one-dimensional pores aligned along a compact hexagonal packing are of prime importance and can be referred to as "hexagonal mesoporous materials" (HMPM). The most famous silica structures of this kind are MCM-41 and SBA-15. The same symmetry can be found in carbon mesoporous materials, for example in FDU-15 structures. The precise characterization of HMPM is necessary for most of the applications envisioned for these materials (pore size, pore density, specific surface and sometimes thickness of the functionalization layer). Small angle X-ray scattering techniques offer the opportunity to determine the mean structural parameters of HMPM. Although different approaches can be found in the literature in order to numerically reproduce the experimental data obtained on HMPM or hexagonal liquid crystals, when the sample is a powder, fitting the experimental data in absolute scale with numerical models becomes necessary. However, with a large scattering contribution of grain at low q vector as well as short range correlation contribution at large q, the analysis is not so simple. In this paper, we propose a comprehensive study [1] devoted to the quantitative interpretation of small-angle scattering patterns of HMPM in terms of structure and specific surface estimation based on the formalism proposed by Spalla et al. [2]. In the case of two real samples, namely a SBA-15 and a MCM-41 powder, the specific surface area of the mesopores is estimated and is discussed in the light of gas adsorption measurements.

Download Full-text