Observation of the Phase Mode in the Incommensurate Phase of K₂SeO₄ by Raman Scattering

抄録

The phase mode has been experimentally studied over a temperature range from the commensurate phase to the incommensurate one in K₂SeO₄, using a Raman scattering instrument of high sensitivity. As a result, the phase mode has been observed to manifest itself in the incommensurate phase. It is found that the phase mode is considerably overdamped and the scattered intensity integrated over the frequency region higher than 2.5 cm⁻¹ increases as the temperature decreases in the incommensurate phase.