Phonon characteristics and dielectric properties of a phase pure CoWO4 ceramic

Abstract A phase pure CoWO4 ceramic was prepared using the conventional solid-state reaction method and sintering at 1150 °C for 2 h. The sintered sample exhibited a tetragonal wolframite structure (space group P2/c) without impurity phases according to X-ray diffraction analysis. The Raman and infrared spectra of the CoWO4 ceramic were studied based on Lorentz fitting, a first-principles calculation, the four-parameter semiquantum (4-P) model and the Kramers-Kronig (K-K) transformation to reveal the local structure and intrinsic properties. The infrared spectrum was fitted based on the 4-P model, which showed that the simulated properties are similar to the experimental results and that the largest contribution to the dielectric response comes from the Bu(1) mode, which is related to the stretching vibration of the WO6 octahedra.