scholarly journals GISAXS studies of mesoporous films using a standard laboratory diffractometer

2014 ◽  
Vol 70 (a1) ◽  
pp. C883-C883
Author(s):  
Milen Gateshki ◽  
Alexander Kharchenko ◽  
Patricia Kidd
Keyword(s):  
Photon Counting ◽  
Grazing Incidence ◽  
Low Noise ◽  
Mesoporous Films ◽  
X Ray ◽  
Noise Characteristics ◽  
X Ray Scattering ◽  
Silica Thin Film ◽  
Sample Structure ◽  
Set Up

With the increasing number of GISAXS (Grazing-Incidence Small-Angle X-ray Scattering) applications for the investigation of materials surface nano-structures, comes the demand for a mainstream laboratory capability to run alongside the more established synchrotron facilities. GISAXS poses considerable challenges when scaling the method to fit a multipurpose laboratory instrument, including the achievement of good angular resolution at small scattering radius, the reduction of scatter from the direct beam and the observation of low intensity signals. We have developed a hardware solution that addresses these challenges. The recent availability of small size pixel (55 micron) photon counting detectors with very low noise characteristics has enabled the implementation of new 2D imaging GISAXS hardware for a standard 1.8KW laboratory X-ray source. In this work we present a number of results that illustrate the capabilities of the new experimental set-up based on a standard multipurpose diffractometer. We present GISAXS images and analysis of a mesoporous silica thin film with close-packed hexagonal type ordering of the pores. In [1] we have reported reflectometry results and analysis of this sample structure. The addition of GISAXS information demonstrates the versatility of the multipurpose diffractometer and the strength in combining methods on one instrument. Strongly scattering Ti-filled silica mesoporous films illustrate the relative ease with which GISAXS signals can be recorded, including even the weak signal below the critical angle of the sample (fig.1). The scattering patterns from both samples exhibit subtle departures from a simple symmetry, suggesting that the films may exhibit residual strain. Thin films with vertical mesopores provide their own challenges in the observation of scatter close and parallel to the specularly reflected beam. We present results in which scattering from Co-filled mesopore structures with 37nm pitch can be clearly resolved.

Multi-use high/low-temperature and pressure compatible portable chamber forin situgrazing-incidence X-ray scattering studies

2013 ◽  
Vol 20 (3) ◽  
pp. 474-481 ◽  
Author(s):  
Pilar Ferrer ◽  
Juan Rubio-Zuazo ◽  
Catherine Heyman ◽  
Fatima Esteban-Betegón ◽  
Germán R. Castro
Keyword(s):  
Heat Exchanger ◽  
High Vacuum ◽  
Grazing Incidence ◽  
Ultra High Vacuum ◽  
Operating Pressure ◽  
X Ray ◽  
Heater Element ◽  
X Ray Scattering ◽  
Set Up ◽  
Ray Scattering

The multipurpose portable ultra-high-vacuum-compatible chamber described in detail in this article has been designed to carry out grazing-incidence X-ray scattering techniques on the BM25-SpLine CRG beamline at the ESRF. The chamber has a cylindrical form, built on a 360° beryllium double-ended conflate flange (CF) nipple. The main advantage of this chamber design is the wide sample temperature range, which may be varied between 60 and 1000 K. Other advantages of using a cylinder are that the wall thickness is reduced to a minimum value, keeping maximal solid angle accessibility and keeping wall absorption of the incoming X-ray beam constant. The heat exchanger is a customized compact liquid-nitrogen (LN2) continuous-flow cryostat. LN2 is transferred from a storage Dewar through a vacuum-isolated transfer line to the heat exchanger. The sample is mounted on a molybdenum support on the heat exchanger, which is equipped with a BORALECTRIC heater element. The chamber versatility extends to the operating pressure, ranging from ultra-high vacuum (<10−10 mbar) to high pressure (up to 3 × 103 mbar). In addition, it is equipped with several CF ports to allocate auxiliary components such as capillary gas-inlet, viewports, leak valves, ion gun, turbo pump,etc., responding to a large variety of experiment requirements. A movable slits set-up has been foreseen to reduce the background and diffuse scattering produced at the beryllium wall. Diffraction data can be recorded either with a point detector or with a bi-dimensional CCD detector, or both detectors simultaneously. The system has been designed to carry out a multitude of experiments in a large variety of environments. The system feasibility is demonstrated by showing temperature-dependence grazing-incidence X-ray diffraction and conductivity measurements on a 20 nm-thick La0.7Ca0.3MnO3thin film grown on a SrTiO3(001) substrate.

scholarly journals A multi-slice simulation algorithm for grazing-incidence small-angle X-ray scattering

2016 ◽  
Vol 49 (6) ◽  
pp. 1876-1884 ◽  
Author(s):  
S. V. Venkatakrishnan ◽  
Jeffrey Donatelli ◽  
Dinesh Kumar ◽  
Abhinav Sarje ◽  
Sunil K. Sinha ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Small Angle ◽  
Intensity Variation ◽  
Grazing Incidence ◽  
Refractive Index Profile ◽  
X Ray ◽  
X Ray Scattering ◽  
Sample Structure ◽  
The Fourier Transform ◽  
Ray Scattering

Grazing-incidence small-angle X-ray scattering (GISAXS) is an important technique in the characterization of samples at the nanometre scale. A key aspect of GISAXS data analysis is the accurate simulation of samples to match the measurement. The distorted-wave Born approximation (DWBA) is a widely used model for the simulation of GISAXS patterns. For certain classes of sample such as nanostructures embedded in thin films, where the electric field intensity variation is significant relative to the size of the structures, a multi-slice DWBA theory is more accurate than the conventional DWBA method. However, simulating complex structures in the multi-slice setting is challenging and the algorithms typically used are designed on a case-by-case basis depending on the structure to be simulated. In this paper, an accurate algorithm for GISAXS simulations based on the multi-slice DWBA theory is presented. In particular, fundamental properties of the Fourier transform have been utilized to develop an algorithm that accurately computes the average refractive index profile as a function of depth and the Fourier transform of the portion of the sample within a given slice, which are key quantities required for the multi-slice DWBA simulation. The results from this method are compared with the traditionally used approximations, demonstrating that the proposed algorithm can produce more accurate results. Furthermore, this algorithm is general with respect to the sample structure, and does not require any sample-specific approximations to perform the simulations.

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

Quantifying Multiple Crystallite Orientations and Crystal Heterogeneities in Complex Thin Film Materials

2019 ◽  
Author(s):  
Jonathan Ogle ◽  
Daniel Powell ◽  
Eric Amerling ◽  
Detlef Matthias Smilgies ◽  
Luisa Whittaker-Brooks
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Design ◽  
Grazing Incidence ◽  
Crystallite Orientation ◽  
Miller Index ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientation Distributions ◽  
Orientation Information

<p>Thin film materials have become increasingly complex in morphological and structural design. When characterizing the structure of these films, a crucial field of study is the role that crystallite orientation plays in giving rise to unique electronic properties. It is therefore important to have a comparative tool for understanding differences in crystallite orientation within a thin film, and also the ability to compare the structural orientation between different thin films. Herein, we designed a new method dubbed the mosaicity factor (MF) to quantify crystallite orientation in thin films using grazing incidence wide-angle X-ray scattering (GIWAXS) patterns. This method for quantifying the orientation of thin films overcomes many limitations inherent in previous approaches such as noise sensitivity, the ability to compare orientation distributions along different axes, and the ability to quantify multiple crystallite orientations observed within the same Miller index. Following the presentation of MF, we proceed to discussing case studies to show the efficacy and range of application available for the use of MF. These studies show how using the MF approach yields quantitative orientation information for various materials assembled on a substrate.<b></b></p>

Strain Analysis in Thin La1−xCaxMnO3 Films by Grazing Incidence X-ray Scattering

1999 ◽  
Vol 602 ◽  
Author(s):  
M. Petit ◽  
L. J. Martinez-Miranda ◽  
M. Rajeswari ◽  
A. Biswas ◽  
D. J. Kang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Strain Analysis ◽  
Grazing Incidence ◽  
Relaxation Processes ◽  
Near Surface ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractWe have performed depth profile analyses of the lattice parameters in epitaxial thin films of La1−xCaxMno3 (LCMO), where x = 0.33 or 0.3, to understand the evolution of strain relaxation processes in these materials. The analyses were done using Grazing Incidence X-ray Scattering (GIXS) on films of different thicnesses on two different substrates, (100) oriented LaAlO3 (LAO), with a lattice mismatch of ∼2% and (110) oriented NGO, with a lattice mismatch of less than 0.1%. Films grown on LAO can exhibit up to three in-plane strained lattice constants, corresponding to a slight orthorhombic distortion of the crystal, as well as near-surface and columnar lattice relaxation. As a function of film thickness, a crossover from a strained film to a mixture of strained and relaxed regions in the film occurs in the range of 700 Å. The structural evolution at this thickness coincides with a change in the resistivity curve near the metalinsulator transition. The in-plane compressive strain has a range of 0.2 – 1.5%, depending on the film thickness for filsm in the range of 400 - 1500 A.

Evolution of Interfacial Roughness Correlations of Fe Au Films Grown on Mgo(001) Substrates

1996 ◽  
Vol 440 ◽  
Author(s):  
P. C. Chow ◽  
R. Paniago ◽  
R. Forrest ◽  
S. C. Moss ◽  
S. S. P. Parkin ◽  
...  
Keyword(s):  
Thin Films ◽  
Diffuse Scattering ◽  
Perfect Match ◽  
Grazing Incidence ◽  
Interface Roughness ◽  
Metallic Structures ◽  
X Ray ◽  
Dimensional Image ◽  
X Ray Scattering ◽  
Image Plate Detector

AbstractThe growth by sputtering of a series of thin films of Fe/Au on MgO(001) substrates was analyzed using Bragg and diffuse X-ray scattering. The Fe (bcc) layer grows rotated by 45° with respect to the MgO – Au(fcc) (001) epitaxial orientation, resulting in an almost perfect match between the two metallic structures. By collecting the X-ray diffuse scattering under grazing incidence using a 2-dimensional image plate detector, we mapped the reciprocal space of these films. We characterized the correlated interface roughness starting with a buffer of Fe in which only three interfaces are present. The propagation of the roughness was subsequently characterized for Fe/Au multilayers with 40 and 100 bilayers. We observe an enlargement of the surface features as a function of time, evidenced by the longer lateral cutoff length measured for thicker films.

An X-ray scattering study on inverted Ge–Si huts grown at low temperatures

2004 ◽  
Vol 19 (4) ◽  
pp. 347-351
Author(s):  
J. Xu ◽  
X. S. Wu ◽  
B. Qian ◽  
J. F. Feng ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Lattice Strain ◽  
Lattice Mismatch ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Scattering Study

Ge–Si inverted huts, which formed at the Si∕Ge interface of Si∕Ge superlattice grown at low temperatures, have been measured by X-ray diffraction, grazing incidence X-ray specular and off-specular reflectivities, and transmission electron microscopy (TEM). The surface of the Si∕Ge superlattice is smooth, and there are no Ge–Si huts appearing on the surface. The roughness of the surfaces is less than 3 Å. Large lattice strain induced by lattice mismatch between Si and Ge is found to be relaxed because of the intermixing of Ge and Si at the Si∕Ge interface.

A general model for estimating the ordering of mesoporous film by grazing incidence small angle X-ray scattering

2014 ◽  
Vol 115 (20) ◽  
pp. 204311 ◽  
Author(s):  
Nie Zhao ◽  
Chunming Yang ◽  
Qian Zhang ◽  
Xueming Lu ◽  
Yuzhu Wang ◽  
...  
Keyword(s):  
Small Angle ◽  
General Model ◽  
Grazing Incidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Mesoporous Film ◽  
Ray Scattering
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