Pressure-Induced Phase Transition of V₂O₃

In situ high pressure experiment of V₂O₃ is carried out by means of synchrotron radiation angle dispersive x-ray diffraction with the diamond anvil cell technique up to about 42 GPa at room temperature. A reversible phase transition unreported previously is observed at above 31 GPa. The c-axis compressibility of corundum-type V₂O₃ shows an abnormal behavior, i.e., the axial length increasing up to 9 GPa then decreasing at higher pressures, which could be attributed to the 3d electronic interaction. The results of compression for V₂O₃ are described by the second-order Birch–Murnaghan equation of state with V₀=300.2(4) ?³ and B₀=255(9) GPa.