Raman Spectroscopic Studies of the Phase Transitions in Hexane at High Pressure

Raman spectroscopic study of n-hexane was carried out in a cubic zirconia anvil cell up to approximately 2.0 GPa. Under high pressure, the C–H stretching region of the spectrum at 2850–3000 cm−1 shows measurable changes in frequency, bandwidth, and intensity. These Raman bands shift towards higher frequencies with increasing pressure. At about 1.4 GPa, phase transition from liquid to solid was induced by compression, as was simultaneously observed with the built-in microscope.