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Nano-polycrystalline diamond has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. The advantage and capability of nano-polycrystalline diamond anvils is discussed by a comparison of the glitch map with that of single-crystal diamond anvils., Nano-polycrystalline diamond (NPD) [Irifune et al. (2003 ▶), Nature (London), 421, 599] has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. In the case of conventional single-crystal diamond (SCD) anvils, glitches owing to Bragg diffraction from the anvils are superimposed on X-ray absorption spectra. The glitch has long been a serious problem for high-pressure research activities using X-ray spectroscopy because of the difficulties of its complete removal. It is demonstrated that NPD is one of the best candidate materials to overcome this problem. Here a glitch-free absorption spectrum using the NPD anvils over a wide energy range is shown. The advantage and capability of NPD anvils is discussed by a comparison of the glitch map with that of SCD anvils.

An X-ray magnetic circular dichroism experiment under multiple extreme conditions, 2

Preparations are underway for the experimental investigation of the roughness of magnetic interfaces in rare-earth multilayers by combining the grazing-angle X-ray scattering technique with the resonant magnetic scattering of hard X-rays. Theoretical considerations show that for small scattering angles, 2theta, the asymmetry ratio, A = [I(+) - I(-)]/[I(+) + I(-)], depends on 2theta and varies as 1/cos theta. The first step towards the goal of determining the magnetic roughness has been taken by measuring the chemical roughness (via specular reflectivity) of a Gd thin-film sample at five photon energies close to the L(3) absorption edge, which yielded the dispersion corrections, f' and f'', to the Gd atomic form factor in good agreement with the calculation of CromerLiberman [J. Chem. Phys. (1970), 53, 1891-1898].