High pressure Raman study of LiClO4

Lithium perchlorate (LiClO4), as one of the new high-energy oxidizers, is chosen for high pressure Raman research to gain a better understanding of the structure and stability, which is very important for the performance of an explosive. Raman spectra of LiClO4 crystal have been measured from ambient to 25.07 GPa with diamond anvil cells (DACs) at room temperature to investigate the structural stability of this system. Raman vibrational modes of LiClO4 crystal at ambient pressure were resolved comprehensively on the basis of our experimental and calculated results. Upon increase of pressure on LiClO4 crystal sample to 1.96 GPa, it was found that the LiClO4 crystal exhibited a pressure-induced first-order phase transformation behavior. The occurrence of a second phase transformation of LiClO4 crystal induced by pressure was observed at about 5.09 GPa. Both phase transformations were demonstrated based on the detailed spectroscopic analysis of the variations in the number of lattice modes, splitting of Raman bands and frequency jumps of the Raman vibrational modes of LiClO4 crystal.