Lattice dynamical investigations for Raman and infrared frequencies of Bi2WO6

Theoretical studies on infrared and Raman-active phonons in the Aurivillius ferroelectric Bi2WO6 were performed. These Raman and infrared phonons were calculated by applying a short-range force constant model using normal coordinates having space group P21ab. The calculations of the zone center phonons have been made with nine stretching, one repulsive and 12 bending force constants. The calculated Raman and infrared wavenumbers are in very good agreement with the experimental ones. The potential energy distribution has also been investigated for determining the significance of contribution from each force constant toward the Raman and the infrared wavenumbers.

► Infrared and Raman-active phonons calculated in Aurivillius ferroelectric Bi2WO6.
► Short-range force constant model used within normal coordinate framework.
► Symmetry coordinates for Aurivillius Bi2WO6 are derived for the first time.
► Calculated phonons are in very good agreement with experiment.