Abstract
High pressure Raman spectroscopic investigations have been carried out on Cs2SO4 up to a pressure of 164kbar. The behaviour of the internal modes of sulphate ions as a function of pressure are examined. In contrast to other disulphates, cesium sulphate does not exhibit any phase transition up to the highest pressures reached in the present investigations. Present results are discussed in the light of earlier studies on other disulphates.