Powder diffraction from compressed molecular hydrogen in a diamond-anvil cell

We report the first observation of x-ray powder-diffraction from molecular hydrogen in a diamond-anvil cell obtained at the European Synchrotron Radiation Facility using image-plate recording techniques. The sample was prepared by compression of hydrogen together with nickel powder in the high-pressure chamber. This result suggests that structural phase transitions in solid hydrogen could be studied directly with powder x-ray techniques. copyright 1997 American Institute of Physics