Raman Spectra Study of the Pressure-induced Phase Transition in β—BaB₂O₄ Crystal

High-pressure Raman study of the β—BaB₂O₄ crystal has been carried out from 0 to 28 kbar with a gasketed diamond anvil cell. The external vibrational modes have been assigned according to the high-pressure Raman spectra. The Raman study reveals the occurrence of pressure-induced phase transition near 10 kbar. 122 cm^-1 peak splitted into two components at pressure above 10 kbar, this is attributed to the lower symmetry of the crystal structure.