High-Pressure Transitions of Germanium and a New High-Pressure Form of Germanium

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Science  19 Feb 1965:
Vol. 147, Issue 3660, pp. 860-862
DOI: 10.1126/science.147.3660.860


Some transitions in germanium and other semiconductor systems have been detected after very long exposure to high pressures followed by various quenching techniques. In the case of Ge, a new high-pressure polymorph, Ge-IV, has been synthesized above 110 kilobars with a body-centered-cubic structure. The pressure for the Ge-I ⇀ Ge-III (body-centered-tetragonal structure) transition has been revised from about 120 to 25 kilobars at 30°C. The transition from the Ge-I (diamond structure) to the Ge-II (white tin structure) is metastable up to 140 kilobars. Thus some phase diagrams based on discontinuities observed in essentially dynamic systems may be inaccurate.