Immaphase of germanium at ∼80 GPa

Ge has been studied to 81 GPa with angle-dispersive diffraction techniques, using an image-plate area detector and high-brilliance synchrotron radiation from the European Synchrotron Radiation Facility. A previously unknown phase of Ge, with orthorhombic symmetry Imma, is found to exist above {~}75 GPa---between the well established β-tin and simple hexagonal phases. This phase is the same as that found recently between the β-tin and simple hexagonal phases of Si.