High pressure Raman spectroscopic study of structural phase transition in samarium oxide

High pressure Raman spectroscopic study of Sm2O3 poly crystal was performed up to 21.0 GPa and room temperature using a diamond anvil cell. Pressure induced phase transition was observed at 2.6 GPa in the pressure increasing process. This phase transition corresponds to the monoclinic B type phase fi the hexagonal A type transformation. The A type phase was stable up to 21.0 GPa. In the pressure release process, the A type phase was stable above 1.8 GPa, and was completely reverted to the B type phase at 1.1 GPa. The phase transition was confirmed to be reversible with a hysteresis of approximately 1.0 GPa.