New diamond anvil cell for single-crystal analysis

A new diamond anvil cell was devised for the single-crystal structure analyses under high pressure. The cell is characterized by large single-crystal diamond plates, which are used for the windows and fixed on the table planes of diamond anvils. The diamond plate windows have great advantages for single-crystal diffractometry, such as low x-ray absorption, much higher pressures up to 50 GPa, no powder rings from the window, and wide 2θ-angle (2θ<70°). Great progress of the structure analyses could be made by the combination with synchrotron radiation (SR). The short wavelength of λ=0.407 72 Å (E=30.388 keV) of SR source with 8 GeV 100 mA at SPring-8 was used for the diffraction intensity measurement of SiO2 stishovite (rutile type). These advantages could measure the intensities of much higher order reflections and the precise electron density distribution as a function of pressure was discussed.