Phase transitions in cyclohexane up to 10 GPa

The phase transitions occurring in cyclohexane are studied by Raman spectroscopy in a gem anvil cell up to 10 GPa at room temperature. Full Raman spectra confirm that the metastable phase occurring at low temperatures at room pressure is the stable crystalline phase IV appearing above 1.3 GPa at room temperature. The present results clarify the controversial transition to phase V, which is find to occur around 3.2 GPa and accompanied by a large hysteresis.