Atypical reversed pressure-induced phase transformation in Ge nanowires
Abstract
Phase transformations of Ge under compression/decompression cycle at room temperature were studied in a diamond anvil cell (DAC) using in situ synchrotron x-ray diffraction, Raman spectroscopy and near infrared absorption techniques. Upon compression similar behavior is observed in nanowires and in bulk although a higher stability is observed in nanowires. The cubic-diamond phase (Ge-3C), the most energetically favorable phase, transforms into the β-tin metallic phase at high pressure and the reverse Ge-β-tin to Ge-3C transformation is generally inhibited by kinetics when pressure is released. While the transformation in Ge bulk leads mostly to Ge-ST12 phase, the loading/unloading cycle of Ge nanowires in DAC leads back to Ge-3C, exhibiting unprecedented size effects. A comprehensive characterization of the final states is described.
- Publication:
-
Nanotechnology
- Pub Date:
- March 2020
- DOI:
- 10.1088/1361-6528/ab7b06
- Bibcode:
- 2020Nanot..31w5711D
- Keywords:
-
- phase transformation;
- pressure diamond anvil cell;
- Raman spectroscopy;
- infrared absorption