Abstract
We report a detailed experimental characterization of the infrared absorption properties of the high pressure, red phase of oxygen. Spectra are measured in the far infrared, down to , in the fundamental vibration and in the overtone regions up to 63 GPa. A new, strong peak is observed at about . Samples less than 0.5 μm thick were produced to measure the strong vibron mode avoiding saturation. We find that the diatomic oxygen molecule is not a good basis to describe the vibrational spectrum of the phase. The spectra can be interpreted in a straightforward way on the basis of an association among the oxygen molecules leading to the formation of units.
- Received 2 July 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.4093
©1999 American Physical Society