Multiferroic and Phonon Properties of the Double Perovskite Pr₂FeAlO₆

Abstract

With the help of a microscopic model and Green’s function technique, we studied the multiferroic and phonon properties of the recently reported new multiferroic Pr2FeAlO6 (PFAO) compound, which belongs to the double perovskite A2BB’O6 family. The magnetization decreases with the increase in temperature and disappears at the ferromagnetic Curie temperature TCFM. The polarization increases with the application of an external magnetic field, indicating strong magnetoelectric coupling and confirming the multiferroic behavior of PFAO. In the curves of dependence of the phonon energy and their damping with respect to temperature, a kink is observed at TCFM. This is due to the strong anharmonic spin–phonon interactions, which play a crucial role below TCFM and are frequently observed in other double perovskite compounds. Above TCFM, only anharmonic phonon–phonon coupling remains. The phonon mode is controlled by an external magnetic field.

Keywords

• Pr₂FeAlO₆
• magnetoelectric effect
• phonon energy
• microscopic model
• Green’s function theory