Yang Y, Bai L G, Zhu K, Liu Y L, Jiang S, Liu J, Chen J, Xing X R
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
J Phys Condens Matter. 2009 Sep 23;21(38):385901. doi: 10.1088/0953-8984/21/38/385901. Epub 2009 Aug 24.
We have reported a Raman scattering investigation of bismuth ferrite (BiFeO(3)) under high pressure up to 50 GPa. Distinct changes in the Raman spectra show evidence for three pressure-induced structural transitions. The abrupt frequency redshifts of the Raman modes near 300 cm(-1) at around 3 GPa are attributed to the modulation of the FeO(6) octahedral tilts. The disappearance of the modes below 250 cm(-1) at 8.6 GPa, together with the enhancement of the two modes in the range of 300-400 cm(-1), indicate the phase transition from the rhombohedral to orthorhombic symmetry. Afterward, the E-3 and E-4 modes disappear at 44.6 GPa, pointing to the occurrence of the orthorhombic-cubic phase transition, which is consistent with the previous postulate that an orthorhombic-cubic transition takes place across the metal-insulator transition at high pressures.
