Pressure-induced phase transitions in the multiferroic perovskite BiFeO3 studied by far-infrared micro-spectroscopy

TL;DR

This study investigates pressure-induced structural phase transitions in multiferroic BiFeO3 using far-infrared micro-spectroscopy, revealing two phase transitions at specific pressures and supporting previous Raman and X-ray findings.

Contribution

It provides new insights into the pressure-dependent phonon behavior and phase transitions in BiFeO3 through far-infrared spectroscopy, complementing existing structural studies.

Findings

Two phase transitions at approximately 3.0 and 7.5 GPa

Infrared-active phonon modes show clear pressure dependence

Supports previous Raman and X-ray diffraction results

Abstract

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.