Calculation of the optical phonons in ordered Ba2MgWO6 perovskite using short-range force field model

Abstract: Ba2MgWO6 is a double perovskite tungstate presenting a cubic structure with cubic space group Oh5. This B-site ordered system has potential applications as microwave ceramics in communication systems. Here, we present our results on the lattice dynamics calculations using short-range force field model to describe both Raman (A(1g) circle plus E-g circle plus 2F(2g)) and infrared (4F(1u)) optical phonons at Gamma-point of the Brillouin zone in Ba2MgWO6 perovskite. Short-range interactions were parameterized through four stretching and three bending force constants in light of the Wilson’s GF-matrix method. Satisfactory agreement between experimental and calculated vibrational data was found. We have used the potential energy distribution (PED) coefficients to determine the contribution of each force constant to the optical modes. The PED analysis elucidates that the W atom has a nonnegligible contribution in describing both A(1g) breathing and Last-type (F-1u) modes. Such a modeling provided insights into vibrational modes, enabling correlation between optical phonons, disorder effects, and physical properties for applications.

Author(s): Rodrigues, JE; Bezerra, DM; Hernandes, AC

JOURNAL OF RAMAN SPECTROSCOPY

DOI: 10.1002/jrs.5460