Surface morphology smoothing of a 2 inch-diameter GaN homoepitaxial layer observed by X-ray diffraction topography

We investigated the surface morphology changes in a 2 inch-diameter, c-plane, free-standing GaN wafer using X-ray diffraction topography in a grazing-incidence geometry.

Coherent Magnetization Rotation of a Layered System Observed by Polarized Neutron Scattering under Grazing Incidence Geometry

The in-plane magnetic structure of a layered system composed of polycrystalline grains smaller than the ferromagnetic exchange length was studied to elucidate the mechanism controlling the magnetic properties considerably different from the bulk using polarized neutron scattering under grazing incidence geometry. The measured result, together with quantitative analysis based on the distorted wave Born approximation, showed that the in-plane length of the area with a uniform orientation of moments ranging from 0.5–1.1 μ m was not significantly varied during the process of demagnetization followed by remagnetization. The obtained behavior of moments is in good agreement with the two-dimensional random anisotropy model where coherent magnetization rotation is dominant.

An X-ray harmonic separator for next-generation synchrotron X-ray sources and X-ray free-electron lasers

An X-ray prism for the extraction of a specific harmonic of undulator radiation is proposed. By using the prism in a grazing incidence geometry, the beam axes of fundamental and harmonics of undulator radiation are separated with large angles over 10 µrad, which enables the selection of a specific harmonic with the help of apertures, while keeping a high photon flux. The concept of the harmonic separation was experimentally confirmed using X-ray beams from the X-ray free-electron laser SACLA.

A multi-functional dual-energy laboratory Mo-Cr-SAXS system

A laboratory small-angle X-ray scattering (SAXS) system with a dual energy (Mo and Cr) source has been designed and established with the aim of studying the heterogeneity in high-Zmetallic structural materials such as steels (Fe alloy) and other materials. With the combination of Mo and Cr energies, various camera lengths (maximum of 2400 mm), and an area detector, three decades ofqrange has been achieved, from 0.024 to 14 nm−1. In real space, the probing periodic distance is a maximum of 261 nm. SAXS profiles of 9Cr-ODS steel powders with good statistics with a measurement time of 6 h show the aptness and viability of this system for the investigation of high-`Z' (high-absorption) metallic structural materials. In addition to having Mo and Cr sources, a flexible sample mounting stage permits measurements on a wide range of materials from soft to hard and liquid to solid, both in transmission and in grazing-incidence geometry.

Stress in Aluminium Alloys Measured Using Göbel Mirror as a Primary Beam Optics of X-Ray Diffractometer

Grazing incidence geometry, called MGID-sin2y, was applied to measure surface stresses in very thin layers (depth of a few mm) of Al-Mg alloy samples subjected to different thermal and mechanical treatments. The Göbel mirror was used to parallelize the incident X-ray beam. Perfect collimation of the beam significantly increases accuracy of determined peak position and consequently allows to measure low stresses in surface layers.