High-pressure Raman scattering and structural phase transition in YCrO4

The high-pressure structural properties of the zircon-type YCrO4 with space group I4(1)/amd were investigated using Raman scattering techniques in a diamond anvil cell up to 28.9 GPa at room temperature. The abrupt changes in Raman spectra indicate that a pressure-induced structural phase transition occurs at a lower pressure 3.0 GPa, but a wide pressure region up to 15.1 GPa is needed to complete this phase transition. Moreover, the high-pressure phase can be quenched at ambient conditions. We calculated the mode Gruneisen parameters and assigned the new phase to be a scheelite-type structure in I4(1)/a symmetry based on the fact that the Raman spectrum of the new phase is similar to that of the scheelite-type YCrO4 prepared at moderate pressure and temperature conditions. The effects of 3d(1) electronic configuration on phase transition pressure and unusual Raman vibrations were discussed.