Raman scattering in alkali azides at high pressures

Abstract

The volume dependence of Raman scattering in sodium, potassium and rubidium azides, measured for the first time to purely hydrostatic pressures of about 40 kbar, shows interesting features. In KN 3, there is an increase in the relative intensity of the E g translational mode with increasing pressure, whereas in isostructural RbN 3, an anomalous decrease in this mode frequency was observed. Fairly large increases in the frequencies of the N 3 − librational modes were found in all three azides. The possible implications of some of the results with regard to pressure induced phase transitions in these materials are discussed.