Infrared reflectivity of GeS

Abstract

Infrared reflectivity measurements at room temperature and 77K are reported for all three principal polarisations. The hitherto missing B1u phonon is shown to have a frequency of 315 cm-1. A new order of pairing with the known Raman active modes is suggested and the resulting splitting factors and force constant ratios calculated. The work suggests that GeS is even less anisotropic than has been thought up to the present.