  We present the results of pressure-dependent far-infrared reflectivity
measurements on the multiferroic perovskite BiFeO3 at room temperature. The
observed behavior of the infrared-active phonon modes as a funtion of pressure
clearly reveals two structural phase transitions around 3.0 and 7.5 GPa,
supporting the results of recent Raman and x-ray diffraction studies under
pressure. Based on the pressure-dependent frequency shifts of the
infrared-active phonon modes we discuss the possible character of the phase
transitions.
