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A high-precision diffractometer has been developed for the structure analysis of a submicrometre-scale single grain of a powder sample at the SPring-8 BL40XU undulator beamline. The key design concept is the combination of a stable focused synchrotron radiation beam and the precise axis control of the diffractometer, which allows accurate diffraction intensity data of a submicrometre-scale single powder grain to be measured. The phase zone plate was designed to create a high-flux focused synchrotron radiation beam. A low-eccentric goniometer and high-precision sample positioning stages were adopted to ensure the alignment of a micrometre-scale focused synchrotron radiation beam onto the submicrometre-scale single powder grain. In order to verify the diffractometer performance, the diffraction pattern data of several powder grains of BaTiO(3), of dimensions approximately 600 x 600 x 300 nm, were measured. By identifying the diffraction data set of one single powder grain, the crystal structure was successfully determined with a reliable factor of 5.24%.

Organically-modified layered titanates (OMLTs) were used as new layered fillers to prepare poly(p-phenylenesulfide) (PPS)-based nanocomposites. The melt mixing of PPS with any OMLT led to the delamination of stacked titanate layers, regardless of the miscibility between intercalants of OMLTs and PPS, and attained a nanoscale dispersion of titanate layers which is an exfoliation structure in the PPS matrix. Transmission electron microscopy (TEM) analysis and X-ray diffraction (XRD) measurement confirmed that titanate layers were successfully dispersed in the PPS matrix. OMLTs had a specific delamination mechanism, which is governed by melt mixing temperatures. In the melt processing at high temperature, the delamination of stacked-layers in OMLTs was facilitated by retaining an initial interlayer spacing of the layered structure and decreasing the surface charge density of the titanate crystal. [ABSTRACT FROM AUTHOR]

An ultra-high-precision clock system for long time delay has been developed for picosecond time-resolved x-ray diffraction measurements using synchrotron radiation (SR) pulses and synchronized femtosecond laser pulses. The time delay control between pump laser pulse and the probe SR pulse was achieved by combining an in-phase quadrature modulator and a synchronous counter. This method allowed us to change the delay time by a nearly infinite amount while maintaining the precision of ±8.40 ps. Time-resolved diffraction measurements using the delay control system were demonstrated for precise measurement of an acoustic velocity in a single crystal of gallium arsenide. [ABSTRACT FROM AUTHOR]

The three-dimensional atomic configuration of amorphous Ge2Sb2Te5 and GeTe were derived by reverse Monte Carlo simulation with synchrotron-radiation x-ray diffraction data. The authors found that amorphous Ge2Sb2Te5 can be regarded as “even-numbered ring structure,” because the ring statistics is dominated by four- and six-fold rings analogous to the crystal phase. On the other hand, the formation of Ge–Ge homopolar bonds in amorphous GeTe constructs both odd- and even-numbered rings. They believe that the unusual ring statistics of amorphous Ge2Sb2Te5 is the key for the fast crystallization speed of the material. [ABSTRACT FROM AUTHOR]