Glitch-free X-ray absorption spectrum under high pressure obtained using nano-polycrystalline 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.