β-tin→Imma→sh phase transitions of germanium
Xiao-Jia Chen1, Chao Zhang, Yue Meng
1Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
Abstract:
New paths were designed for the investigations of the β-tin→Imma→sh phase transitions in nanocrystalline Ge under conditions of hydrostatic stress. A second-order transition between the β-tin and Imma phases was identified at 66 GPa, and a first-order transition between the Imma and sh phases was determined at 90 GPa. Superconductivity was obtained up to 190 GPa using the acquired structural data in first-principles calculations. This provides evidence that the standard electron-phonon coupling mechanism is responsible for superconductivity in Ge, as evidenced by the good agreement between the calculations and existing experiments.
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