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A single-beam optical-trap sample holder for X-ray diffraction measurements with synchrotron radiation has been developed. The sample holder was used to obtain an X-ray diffraction image of a single ZnO particle levitated in air, without mechanical contact, by the optical gradient force exerted by a focused laser beam. The diffraction image showed a Debye ring pattern, which was similar to a powder diffraction pattern of an assemblage of ZnO particles. While the ZnO particle is held by the optical trap in air, it rotates irregularly. Therefore, the Debye ring pattern of the ZnO particle can be clearly obtained even if the ZnO particle is a single grain. Lattice parameters and crystallite size of the single ZnO particle were determined simultaneously. The lattice parameters were determined to be a = 3.2505 ± 0.0005 Å and c = 5.207 ± 0.006 Å, which are consistent with those of the assemblage of ZnO particles. The crystallite size determined by the Scherrer method was 193.4 ± 26.2 nm.

We measured the thermal expansion coefficients of 18R-LPSO phase and α-Mg phase in a Mg97Zn1Y2 alloy polycrystal. This was achieved by using a Gandolfi camera, which was attached on a high precision diffractometer at SPring-8 BL40XU beamline. By using this system, fine diffraction data were obtained from a Mg97Zn1Y2 polycrystal at 6 different temperatures between 90 and 450 K. We succeeded to determine cell parameters of 18R-LPSO phase and α-Mg phase separately in the Mg97Zn1Y2 alloy polycrystal. The thermal expansion coefficients were determined from the refined cell parameters. The differences of the thermal expansion coefficients of 18R-LPSO phase and α-Mg phase in the Mg97Zn1Y2 alloy were much smaller than those of single-phase 18R-LPSO and α-Mg polycrystals.

We investigated the local strain in a silicon carbide (4H-SiC) (0001) trench metal-oxide semiconductor field-effect transistor (MOSFET) using synchrotron nanobeam X-ray diffraction (nano-XRD) at the SPring-8 BL13XU beamline. Using X-rays incident on the 4H-SiC trench cross section, diffraction measurements were performed on the ( 11 2 ¯ 0 ) and ( 11 2 ¯ 4 ) planes. Intensity maps of the 11 2 ¯ 0 and 11 2 ¯ 4 diffractions yielded images reflecting the trench structure. The spatial resolution of the 4H-SiC 11 2 ¯ 4 intensity map in the [0001] direction was higher than that for the 11 2 ¯ 0 diffraction because the angle of incidence was close to perpendicular to the sample. From two-dimensional reciprocal space maps of the symmetric and asymmetric diffractions, the tilt and the ( 11 2 ¯ 0 ) - and (0004)-plane strain components were individually separated and visualized. A tensile strain of approximately 0.1% was found in the region between the trenches. These results indicate the effectiveness of nano-XRD for strain visualization in trench MOSFETs and similar electronic devices.

When controlling electronic properties of bulk materials, we usually assume that the basic crystal structure is fixed. However, in two-dimensional (2D) materials, atomic structure or to functionalize their properties. Various polymorphs can exist in transition metal dichalcogenides (TMDCs) from which 2D materials are generated, and polymorphism has drastic on the electronic states. Here we report the discovery of an polymorph is attracting growing interest as a controlling parameter unprecedented polymorph of a TMDC 2D material. By mechanical exfoliation, we made thin flakes from a single crystal of 2Ha-type tantalum disulfide (TaS2), a metallic TMDC with a charge-density-wave (CDW) phase. Microbeam X-ray diffraction measurements and electrical transport measurements indicate that thin flakes possess a polymorph different from any one known in TaS2 bulk crystals. Moreover, the flakes with the unique polymorph displayed the dramatically enhanced CDW ordering temperature. The present results suggest the potential existence of diverse structural and electronic phases accessible only in 2D materials.

Over the past 20 years, many designer drugs derived from controlled substances have been widely distributed as easily available psychoactive substances and have become a serious problem in Japan. In order to determine the absolute structures of four new designer drugs derived from medicines (methylphenidate and phenmetrazine) X-ray single-crystal structure analyses were performed using the BL26B1 beamline of synchrotron radiation facility SPring-8. The results show that the molecular configuration of these designer drugs (having two asymmetric carbons), which were distributed in the illegal drug market had threo-forms as found for methylphenidate and phenmetrazine.

A high-Ge-content Si1–yGey/compositionally graded Si1–xGex-stacked structure grown on Si(001) is now considered to be an important platform for the realization of advanced nanometer-scale complementary metal oxide semiconductor devices with high-mobility channel materials, such as III–V materials and Ge, and monolithically integrated photonic modules. The performance of such advanced devices is critically influenced by crystalline inhomogeneity in the stacked structure; therefore, precise characterization of the crystallinity is important. In particular, the development of a characterization method not only for in-plane crystallinity but also for in-depth crystallinity is strongly required. This is because the crystalline quality of the constant composition Si1–yGey is sensitively dependent on that of the compositionally graded Si1–xGex layers underneath. Here, we have demonstrated in-depth tomographic mapping of a high-Ge-content Si1–yGey/compositionally graded Si1–xGex-stacked structure using position-d...

Two types of optical choppers for time-resolved measurements in soft X-ray beamlines of synchrotron radiation facilities were developed, which are utilized under ultra-high-vacuum conditions., Two types of optical choppers for time-resolved measurements at synchrotron radiation soft X-ray beamlines have been developed. One type uses an air-spindle-type rotation mechanism with a two-stage differential pumping system to maintain the ultra-high vacuum of the X-ray beamline, and the other uses a magnetic bearing. Both can be installed at the soft X-ray beamlines at SPring-8, greatly improving the accessibility of pump-and-probe spectroscopy. The combination of X-ray chopper and pump-and-probe photoemission electron microscope at SPring-8 provides drastic improvements in signal-to-noise ratio and resolution compared with techniques using high-voltage gating of channel plate detectors. The choppers have the capability to be used not only at synchrotron radiation facilities but also at other types of soft X-ray and VUV beamlines.

We examined the formation of locally strained Ge nanostructures sandwiched between Ge1−x Sn x stressors using metal-organic chemical vapor deposition method. We have investigated the microscopic local strain and stress in the Ge/Ge1−x Sn x heterostructures using synchrotron microdiffraction and finite element method calculation. The microdiffraction measurement for an asymmetric lattice plane enables directly quantitative evaluation of the strain value of an individual Ge fine line structure with a few tens of nanometers width. An in-plane compressive strain value of 0.9% is achieved for a 30 nm-width Ge line with Ge1−x Sn x stressors, which corresponds to a compressive stress of 1.2 GPa.

The range of polishing-induced subsurface damage remaining in a commercially available production grade 4H-SiC (0001) epi-ready substrate was evaluated by the observation from the (-1100) cleavage plane using two kinds of highly strain-sensitive characterization methods. Firstly, the analysis using electron backscattered diffraction (EBSD) with a submicron spatial resolution was conducted on the exposed cross sectional plane. Then, for the further quantitative evaluation excluding the influence of roughness or contamination of the cleavage plane, a synchrotron X-ray micro-diffraction experiment was carried out. The range of the subsurface damage evaluated in those experiments was ensured by confirming none of additional strain inserted at the cleavage, as compared with the damage-free substrate prepared by high temperature thermal etching. As a result, the depth of the residual strained region below polishing-induced scratches at the surface was estimated to be in the range of a few microns, which is much deeper than the previously reported value of 100 nm by cross-sectional transmission electron microscopy. It suggests a potential of EBSD for the conventional tool to characterize even a small amount of strain in SiC single crystal.

Au redistribution layers 10 to 100 μm wide were fabricated on heterogeneously integrated advanced flexible hybrid electronics (FHE) substrates formed by a die-first approach based on fan-out wafer-level packaging. The formed Au metal wiring was meticulously studied for locally induced mechanical stress upon bending (bending radius, BR 20 mm) using Laue microdiffraction (LμD) with synchrotron radiation. It was inferred from the LμD data that upon bending the FHE substrate up to the BR of 20 mm, the Au metal wiring (10 mm long, 100 μm wide, and 500 nm thick) experienced mechanical bending stress amounting to 250 ∼ 300 MPa. The stress values obtained from the LμD studies were close to the stress value of 350 MPa obtained by simulation.

Hydrogen as an energy carrier faces challenges such as high costs of hydrogen supply, high cost of fuel cell electric vehicles (FCEVs), and substantial infrastructure requirements. However, leading countries have announced long-term plan and targets in developing hydrogen energy. Should the Association of Southeast Asian Nations (ASEAN) follow up such developments? This study asks if hydrogen-based road transport, especially FCEVs in the fleets of passenger cars, buses, and trucks, could be economically justified in the ASEAN member states. If not, what strategies to take for ASEAN member states? The study applies a well-to-wheel model and a total cost of ownership model to compare the energy consumption, carbon emissions, as well as the costs of FCEVs with those of alternative powertrains. This practice shows the scale of the cost gaps. Subsequently, it estimates the implications of predicted future developments of both hydrogen and FCEVs, in terms of costs and carbon emissions reduced. The results indicate the areas in which FCEVs are most likely to become competitive in the near future, and thus could be targeted and prioritised. By comparing the country-specific results, implications are extended to what policies are most relevant in facilitating the development of hydrogen and fuel cell.

We report current status of a synchrotron nanobeam X-ray diffraction (nanoXRD) station at SPring-8. The nanoXRD station is located at the 4th experimental hutch of the surface and interface structure beamline BL13XU. The 4th hutch, that was constructed in March 2015, is dedicated for the nanoXRD experiments. There are two types of focusing optics available at the station; a zone plate (ZP) and compound refractive lenses (CRLs). The ZP is used to focus X-rays with energy range from 8 to 15 keV. The minimum beam size of 110 × 150 nm2 is available with the ZP. CRLs made of quartz glass are used for high energy X-rays up to 30 keV. Beam size at 30 keV is 1.6 × 1.6 µm2 and the flux is 1.2 × 1010photons/s. Our main target samples are single crystalline thin films or nano-rods grown on substrates. Cross sectional observations of thick film have also been started. Users can align samples to the rotation center of the goniometer rapidly by preparation using an offline stage that is synchronized to an online stage. In addition, we have developed semi-automatic sample alignment system, that can align any position on a sample surface to the rotation center even if the sample has non-flat surface, like badly cleaved section of a crystal. Details of the station and equipments are introduced.

We realized the milliseconds rapid diffraction measurement using the high-flux synchrotron radiation (SR) of SPring-8 and a high frame rate photon counting detector in BL40XU beamline. We carried out single crystal X-ray diffraction measurements at high rotation speeds up to 80,000 rpm (0.75 ms/rotation) in order to evaluate the limitations of the measurement time and the accuracy of molecular structure. Using a high-speed spindle motor for sample rotation, we successfully analyzed the structure of cytidine (C9H13N3O5) from a dataset of a 60 ms measurement time at a 1,000 rpm sample rotation. However, although weak diffraction spots were clearly observed, the crystal structure could not be solved at an 80,000 rpm sample rotation. These results show that it is possible to observe the crystal structure or lattice parameter changes during one-shot irreversible chemical reactions using the millisecond rapid diffraction measurement.

This chapter provides two different X-ray microdiffraction methods to define optical devices with highly brilliant synchrotron radiation. It demonstrates that the two methods were useful for the accurate-analysis of mask width dependent strain change and lattice strain distribution in selective area growth layers. Selective metal-organic vapor phase epitaxial (MOVPE) growth of lnGaAsP layers on a narrow stripe region along the direction of an InP substrate between a pair of dielectric stripe masks is an attractive method for fabricating integrated photonic devices. The lnGaAsP layers and InP cap layers were grown by atmospheric pressure MOVPE in the unmasked regions. The direction of the sample was set parallel to the horizontal plane on the sample stage, to scan the measuring position across the narrow-stripe region of selectively grown layers. The chapter examines the strain distribution in selectively grown layers using the high-spatial-resolution microdiffraction system.

We have investigated the microscopic crystalline morphology such as lattice plane tilting and defects in semipolar (20–21) GaN films grown on (22–43) patterned sapphire substrates (PSS) by using position-dependent ω–2θ map measurement of X-ray microdiffraction (XRMD) combined with transmission electron microscopy (TEM). The results of the position-dependent ω–2θ map measurement for the GaN (20–21) plane showed periodic variation of the diffraction spot shapes depending on the patterning pitch of the PSS. Broadening of the diffraction spots in the terrace area and single diffraction spots in the grooved one were also observed. These results indicate that the lattice plane tilting of the GaN film depends on the PSS structure and the presence of the defective GaN film on the terrace area where basal plane stacking-fault generation occurred, as confirmed by TEM.

The microscopic crystalline structure (MCS) such as domain texturing, lattice tilting fluctuation and strain fluctuation in thick AlN films grown on trench-patterned AlN/α-Al2O3 templates was clarified by utilizing position-dependent X-ray microdiffraction measurements in combination with transmission electron microscopy observations. The results clearly demonstrate that the trench-patterned templates have a strong influence on the MCS in the thick AlN films. The MCS is anisotropic between the [ 11 2 ¯ 0 ] and [ 1 1 ¯ 00 ] directions. Periodic domain texturing was observed along the [ 11 2 ¯ 0 ] direction, corresponding to the periodicity of the patterning pitch of the template. Submicron crystal domains are tilted at different angles to the [ 11 2 ¯ 0 ] direction, and the crystal domain tilting becomes larger in the void-containing trench regions than in the terrace regions. This generates the periodicity in lattice tilting fluctuation and strain fluctuation along the [ 11 2 ¯ 0 ] direction. These were found to be caused primarily by two factors; one of which being the elastic strain relaxation that depends on the growth direction in the terrace regions, and the other being the inhomogeneity in distribution and morphology of dislocations that have Burgers vectors with a screw component in the void-containing trench regions.

We investigated the temperature dependence of resistivity in thin crystals of FeSe1−xTex (x = 1.0, 0.95, and 0.9), though bulk crystals with 1.0 ≧ × ≧ 0.9 are known to be non-superconducting. With decreasing thickness of the crystals, the resistivity of x = 0.95 and 0.9 decreases and reaches zero at a low temperature, which indicates a clear superconducting transition. The anomaly of resistivity related to the structural and magnetic transitions completely disappears in 55- to 155-nm-thick crystals of x = 0.9, resulting in metallic behavior in the normal state. Microbeam x-ray diffraction measurements were performed on bulk single crystals and thin crystals of FeSe1−xTex. A significant difference of the lattice constant, c, was observed in FeSe1−xTex, which varied with differing Te content (x), and even in crystals with the same x, which was mainly caused by inhomogeneity of the Se/Te distribution. It has been found that the characteristic temperatures causing the structural and magnetic transition (T t), the superconducting transition (T c), and the zero resistivity (T c zero) are closely related to the value of c in thin crystals of FeSe1−xTex.

Development and stability of synchronized long-period stacking ordered (LPSO) structures in Mg97Y2Zn1 alloy were examined by synchrotron-radiation small- and wide-angle scattering/diffraction measurements. The main LPSO structure in the as-cast polycrystalline ingot was 18R, and 14H structure grew at the cost of 18R during annealing. The in-plane peak position increased for longer annealing times in isothermal annealing and also at higher temperatures during in situ heating measurements, and it was interpreted by a composition of peaks corresponding to several sites. The experimental instability temperatures obtained by in situ measurements for in-plane ordering, 18R, and 14H structures agreed within experimental resolution.

We investigated local strain distribution in a cross-sectional area throughout the thickness of a thick aluminum nitride (AlN) film epitaxially grown on a trench-patterned AlN/α-Al2O3 template using X-ray microdiffraction measurements for AlN and Bragg reflections. The results show that the presence of voids caused by the trench pattern strongly influences on the distribution of the strain components in the and directions, which are perpendicular to the trench lines. Discrepancy between strain values obtained from the two Bragg reflections was shown to be the result of twisting of the crystal domains about the axis in the thick AlN film.

In this study, we have examined the formation of uniaxially strained Ge microstructures with embedded Ge 1 − x Sn x epitaxial layers and the microscopic local strain structure in Ge and Ge 1 − x Sn x using synchrotron X-ray microdiffraction and the finite element method. We achieved local heteroepitaxial growth of Ge 0.947 Sn 0.053 layers on the Ge recess regions. Microdiffraction measurements reveal that an average uniaxial compressive strain of 0.19% is induced in Ge locally with Ge 1 − x Sn x stressors. In addition, we found that the Sn precipitation near the Ge 1 − x Sn x /Ge(001) interface occurs after post-deposition annealing at 500 °C without the introduction of dislocation. It is considered that the local Sn precipitation occurs preferentially due to the larger residual stresses near the Ge 1 − x Sn x /Ge interface.

We quantitatively evaluated lattice plane microstructure, which includes lattice plane tilt, spacing, twist, and their fluctuations, in a modified Na-flux GaN bulk single crystal using the synchrotron-based nanobeam X-ray diffraction method. The GaN crystal was fabricated by two-step growth; the first layer had coalescence boundaries as a consequence of faceted growth from the multipoint-seed GaN template, and the second layer grew on the first without faceted growth. Position-dependent ω-2θ- mapping analysis revealed in-plane distribution of local lattice plane microstructure along with dislocation morphology around the coalescence boundary and the growth-stage boundary (GSB). Faceted growth from the multipoint seed template led to concentration of a-type dislocations at the coalescence boundary. These dislocations would glide widely on basal planes above the GSB, and then homogeneously propagate toward the surface. As a result, the modified Na-flux GaN crystal had a homogeneous lattice plane microstructure with little bunching of threading dislocations.