Pressure-induced transformations in the atomic and electronic structure of amorphous germanium (a-Ge) have been investigated by using x-ray absorption spectroscopy XAS combined with energy-scanning x-ray diffraction. Our data show that an abrupt change in the local structure and in the electron states near the Fermi level occurs in evaporated a-Ge at a pressure of about 8 GPa. The transformation is clearly detectable by a change in the shape and energy shift in the near-edge structures and by an increase of the average first-neighbor distance measured by XAS. The occurrence of this polyamorphic transition is discussed in light of the recent advances in the study of multiple dense fluid phases.
Polyamorphic transition of germanium under pressure
DI CICCO, Andrea;
2004-01-01
Abstract
Pressure-induced transformations in the atomic and electronic structure of amorphous germanium (a-Ge) have been investigated by using x-ray absorption spectroscopy XAS combined with energy-scanning x-ray diffraction. Our data show that an abrupt change in the local structure and in the electron states near the Fermi level occurs in evaporated a-Ge at a pressure of about 8 GPa. The transformation is clearly detectable by a change in the shape and energy shift in the near-edge structures and by an increase of the average first-neighbor distance measured by XAS. The occurrence of this polyamorphic transition is discussed in light of the recent advances in the study of multiple dense fluid phases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
