Volume 33(2) - Summer 2017

SmartLab Studio II is an integrated X-ray diffraction software package for making both measurements and analyses using SmartLab, an automated multipurpose X-ray diffractometer. Two years ago(1), the user guidance feature, flow bars, chart control, report manager, SQL database*1, and plugin modules were introduced. Now we would like to announce several new features of SmartLab Studio II for the SmartLab SE system which was launched to the market in April, 2017.

SmartLab SE, which includes a semiconductor detector as a “standard” component, is Rigaku’s newest automated multipurpose X-ray diffractometer system. Customers can select either the “2D” or the “1D” version of this system. If customers select the “2D” model, they can easily determine the degree of preferred orientation and coarse grain size effects from the shape of Debye-Scherrer rings using the hybrid pixel array detector “HyPix-400”. The SmartLab SE configured with a HyPix-400 detector operates in 0, 1, and 2D models without the need to change the detector.

This system also offers the original ease-of-use features of the SmartLab system: automatic alignment, component recognition, and Cross Beam Optics. The guidance software recognizes installed components and seamlessly integrates them into data collection and data analysis methods. The Cross Beam Optics (CBO) module offers permanently mounted, automatically aligned and user-selectable optical geometries for various diffraction experiments. For example, one can choose a Bragg-Brentano optics and parallel beam optics combination for measurements of both powders and thin films without the need for instrument reconfiguration. One can also choose a Bragg-Brentano optics and focusing transmission optics combination to measure organic materials in both transmission and reflection modes.

Figure 1 shows typical sample preparation methods for X-ray fluorescence analysis. In general, the shadowed methods are the most popular. Quality control analysis, which requires high precision, normally requires large samples as much as 20 mm–30 mm in diameter. However, in many cases it is difficult to prepare samples large enough or in sufficient quantity for R&D or troubleshooting. Because these samples are precious, there is a strong requirement to recover them after XRF analysis for other analysis methods. This paper introduces sample preparation methods useful for trace sample (small pieces, small amounts of powder, etc.) analysis.

X-ray fluorescence spectroscopy (XRF) is an elemental quantification analysis method for inorganic and metallic compounds. Sample preparation is simple and does not require solid samples to be dissolved, as is necessary for wet chemical analysis techniques. The fundamental parameter (FP) method implements quantitative analysis without type standards. The XRF technique has been widely accepted not only for bulk analysis but for thin film analysis in plating and electronic materials. With the thin film FP method, the thickness and composition of a thin film can be simultaneously determined, and the software is able to handle even complex multilayers. This article explains the basic principles of XRF thin film analysis; the depth of an XRF measurement and an overview of the thin film FP method. An ITO (indium tin oxide) thin film is analyzed as an example, and software parameter settings and reference material settings are also described.

Single crystal X-ray analysis of proteins involves many hurdles to be overcome, including protein expression, crystallization, data collection and phase determination. Advanced radiation facilities, innovative detector systems, laboratory systems with high-intensity X-ray sources and newly developed software have drastically expanded the range of crystals that can be analyzed. Despite such improvements, there are still some hurdles to be overcome, i.e., quality checking of protein crystals and optimization of freezing conditions. No matter how good device or software may be, crystals of poor quality cannot yield any data suitable for structural analysis. The quality of crystals can deteriorate when frozen under non-optimized conditions, due to crystallization of water contained in the crystals. Even if crystals produce diffraction spots at sufficient resolution for analysis, if any ice rings are present in the image, then the diffraction spots within the ice ring-containing regions need to be excluded, resulting in poor quality and completeness of the data. This manuscript provides some tips for collecting and processing protein crystal data for X-ray analysis.

It is well known that X-rays have wavelengths comparable with interatomic distances and can be utilized for atomic-scale structural determination. In addition, X-rays can penetrate through opaque objects and show the internal structure without destroying the object. It is for these reasons that X-rays are widely used for atomic-scale structural analysis of various kinds of crystals including small molecules and large protein molecules, and in some cases providing accurate electron density information. In addition, small-angle and ultra small-angle X-ray scattering (SAXS, USAXS) is an exceptionally useful technique for evaluating the size, shape, and morphology of higher-order structures in the range of a few nanometers to sub-micrometers. Recently, the resolution of X-ray microscopes has been pushed down to the sub-micrometer level. These devices are also capable of recording computed tomography (CT) data. This is a powerful technique for visualizing the internal structure of various specimens in three dimensions (3D) at the micrometer scale. By utilizing these X-ray techniques, we have the opportunity to investigate a very extended range of multi-scale structures from the atomic-scale (10⁻¹⁰ m) to macroscopic-scale (10⁻² m), continuously for various kinds of materials without destroying the specimens.

In this paper, we will investigate multi-scale structures of a polymer electrolyte membrane (PEM) fuel cell, which generates electricity with catalyst nanoparticles and its support, a proton exchange membrane, a micro-porous layer, a gas diffusion layer, and channels on separator. The sizes of those constituents are spread over nanometers to millimeters and providing the possibility to investigate using state-of-the-art X-ray analysis techniques

The physical and chemical properties of a crystalline solid depend heavily on the conformations of the molecules and the arrangement of atoms and molecules, that is, the “crystal structure”, as well as on the composing elements and molecular structures. The single crystal structure analysis technique is used in many fields as a good tool to precisely clarify the crystal structures required to understand the mechanisms of developing physical properties of crystalline materials.

In recent years, reports of the success of crystal structure analysis from powder X-ray diffraction data are increasing, particularly in regards to polycrystalline samples that were difficult for single crystal structure analysis. In addition to improvements in analysis methods and high performance PCs, one of the major reasons is that very good diffraction data can now be obtained using in-house powder X-ray diffractometers instead of synchrotron facilities due to improvements in X-ray optical devices and detectors.