Effect of the low temperatures on the Raman active vibrational modes in ZnP2 and CdP2

Raman spectroscopy has proven to be a widely used tool for investigation the vibrational properties of diphosphides ZnP2 and CdP2 over a wide range of temperature change. The temperature dependence of the vibrational modes in the diphosphides ZnP2 and CdP2 has been studied by employing Raman spectroscopy in the 3-300 K temperature range. The influence of the temperature on the phosphorus chains in ZnP2 and CdP2 manifests on the magnitude of the frequency dependent shift of the Raman peaks at lower temperatures. As addition evidence of this phenomenon we have shown and discussed the correlation between the magnitude of frequency shift and the orientation of the sample.