Volume 30(2) - Summer 2014

Thermodilatometry is a thermal analysis technique in which a constant load is applied to a sample, and the amount of expansion and/or shrinkage of the sample is measured during heating. TDL 8411 was recently added to the lineup of the Thermo plus EVO2 series as a high-performance thermodilatometer using the horizontal differential expansion system. It is equipped with various new functions, including space-saving design, ECO mode for reducing standby power and an auto sample changer holding 24 samples.

Two types of instruments are available: a standard type with a maximum use temperature of 1100°C (the support tube and detection rod are made of SiO₂), and a high temperature type ranging up to 1500°C (the support tube and detection rod are made of Al₂O₃).

Rigaku’s HyPix-3000 is a next-generation two-dimensional semiconductor detector designed specifically to meet the needs of the home lab diffractionist. One of the HyPix-3000’s unique features is its large active area of approximately 3000 mm2 with a small pixel size of 100 μm square, resulting in a detector with high spatial resolution. In addition, the HyPix-3000 is a single photon counting X-ray detector with a high count rate of greater than 10⁶ cps/pixel, a fast readout speed and essentially no noise.

HyPix-3000 has the following features:

• Ultra-high dynamic range and high sensitivity
• Seamless switching from 2D-TDI (Time Delay and Integration) mode to 2D snapshot mode to 1D-TDI mode to 0D mode with a single detector
• XRF suppression by high and low energy discrimination
• High spatial resolution, direct-detection pixel array detector

Rigaku has developed a new series of single crystal diffractometers that address a wide range of sample types, from small molecules to MOFs, to biological macromolecules. The key component that is common for this series of diffractometers is the use of an HPAD (hybrid pixel array detector), a technology that produces an almost perfect detector and greatly expands the capabilities of a single crystal diffractometer in terms of speed of data acquisition and more accurate measurement of weak data. The standard detector in the XtaLAB PRO series is the PILATUS 200K, a detector that is well proven in the field and based on the same technology adopted by synchrotron beamlines around the world. The outstanding characteristics of these detectors ensure that every XtaLAB PRO diffractometer will perform to produce the best data possible for the X-ray source selected.

SmartLab 3 offers continued refinement of the original ease of use features awarded the R&D 100 Award in 2006: automatic alignment, component recognition, cross beam optics and a five axis goniometer. Award winning guidance software recognizes installed components and seamlessly integrates them into data collection and data analysis methods. The Cross beam optics module offers permanently mounted, permanently aligned and user selectable optical geometries for various diffraction experiments. As an example, one can choose a Bragg–Brentano and parallel beam combination for measurements of both powders and thin films without the need for instrument reconfiguration. One could also choose a Bragg–Brentano and focusing transmission combination to measure organic materials in both transmission and reflection modes. The fifth axis or in-plane axis of the SmartLab allows the measurement of structures that are in the surface plane of the sample. This allows the measurement of extremely thin films and depth profiling in coatings. The SmartLab 3 system further extends application capability with the HyPix-400, a next generation 2-D detector. This hybrid pixel array detector offers the highest resolution and count rates available today. It is fully manufactured and integrated into the SmartLab 3 system by Rigaku and, as such, offers the superior ease of use pioneered by Rigaku in the original SmartLab system model. The SmartLab 3 configured with a HyPix-400 detector operates in 0-, 1-, and 2-D models without the need to exchange a detector.

In the X-ray Fluorescence analysis (XRF) field, it may fairly be said that sample preparation can be the largest factor that cause analysis error. Especially for the analysis of powder samples, as mentioned in the previous edition [Sample preparation for X-ray Fluorescence Analysis I.], heterogeneity effects such as grain size effect, mineralogical effect and segregation can result in analysis error because of its effect on the X-ray fluorescence intensity. When more precise analysis is required, it is recommended to analyze the sample after pulverization to eliminate the grain size effect and segregation as much as possible. For the fusion bead method which can remove the influences of grain size and mineralogical effects, the pulverization of the sample beforehand may be a key point in successfully preparing a homogeneous fusion bead sample with high reproducibility.

This issue describes the important points for pulverization to make powder samples with particle size less than 50 μm.

CIF is an abbreviation for Crystallographic Information File, and these files record all of the information pertaining to crystal structure analysis. A CIF is written as a text file, and thus its content can be checked and edited using ordinary text editing software. CIFs are written with a special-purpose syntax, but they have spread rapidly due to their adoption by the IUCr (International Union of Crystallography), and are indispensible in X-ray structure analysis and related fields. In particular, when submitting papers whose focus is reporting the structure of a molecule, authors are frequently asked to submit a CIF, and there are likely many researchers who have struggled to understand and handle the alerts which appear during checking with checkCIF/PLATON on the IUCr website.

This paper discusses the purpose of and background behind the adoption of CIFs, alerts which frequently appear when checking using checkCIF/PLATON and how to handle them, details on judgment criteria, and vrf’s (validation reply/response forms). To deal with these alerts, one must first be familiar with checkCIF/PLATON, and the author will be thrilled if this paper serves as a opportunity for readers to improve their understanding.

Concerns about the effect of atmospheric aerosol particles have been increasing in recent years and its impact on global climate, air pollution and human health have been studied extensively. Recent reports of extremely high concentration levels of PM2.5 in China have drawn worldwide attention to this issue as well.

PM2.5 are small particles suspended in the atmosphere with diameter less than 2.5 μm. The size is sufficiently small such that breathing can cause the particles to enter deep regions in the lungs where the air and blood are in intimate contact. This has raised concern not only about its effect on the respiratory but also on the cardiovascular system.

Elemental analysis of atmospheric aerosols including PM2.5 is an important means that can provide information about its source and environmental impact. In Japan, for the analysis of inorganic elements of PM2.5, acid decomposition of the collected sample followed by inductively coupled plasma-mass spectrometry (ICP-MS) method has been recommended. However, the sample preparation of this analysis method is complicated and analysis error can vary depending on the operator. Furthermore, the sample can not be recovered after measurement since ICP-MS requires that the sample be dissolved in an acid solution.

To overcome these issues, the Japanese ministry of environment established a “Guideline for Component Analysis of PM2.5” in 2007 which is a simple and nondestructive analysis method of inorganic elements by X-ray fluorescence (XRF) analysis. The guideline was partially revised in 2013 describes the analysis process of PM2.5 by XRF more concretely.

This paper discusses recent methods in X-ray stress analysis. The authors have selected three examples thought to be the most practical from among the many X-ray stress measurement and analysis methods other than the conventional sin2 ψ method. The examples of analyses presented here are: (1) residual stress measurement using the multiple-hkl method, (2) residual stress measurement of samples with shear stress in the depth direction, and (3) residual stress measurement and line-broadening of diffraction in samples with fibre texture using the crystallite strain analysis method.

1.　 International Year of Crystallography 2014

Solid materials in the crystalline state are characterized by a periodic structure, which acts as a diffraction grating at an atomic scale for incident X-rays. The famous experiment of X-ray diffraction, using a zincblende crystal, was suggested by Max von Laue at the University of Munich, Germany and was conducted by W. Friedrich and P. Knipping in 1912. The Nobel Prize in Physics was awarded to Max von Laue in 1914 for his discovery of the X-ray diffraction phenomena, which verified the wave nature of X-rays. Discovery of X-ray diffraction changed the field of mathematical crystallography in the 19th century to an experimental science.

X-ray crystal structure analysis is a reverse process of X-ray diffraction. Intensities at individual diffraction spots recorded on the surface of a detector in reciprocal space are converted into their frequencies, and then inversely Fourier transformed into the crystal structure in real space. The X-ray diffraction method provides us the information about the spatial arrangement of atoms in the crystal lattice together with precise data concerning interatomic distances and bond angles. The three-dimensional information and the highly quantitative nature of the data distinguish X-ray crystallography from other analytical sciences such as microscopy or spectroscopy.

A proposal for celebrating the 100-year anniversary of X-ray crystallography since the discovery of X-ray diffraction was approved at General Assembly of the United Nations, and the year 2014 was assigned as International Year of Crystallography 2014 (IYCr2014). It is our great pleasure that X-ray crystallography has been used as one of the most important tools for materials characterization for more than 100 years.