Detailed structure analyses on Cobalt doped PbTiO3 powders

The identification of the defects and secondary phases which significantly affect the material properties are of crucial importance. In this study, a systematic structure examination of PbTiO3 and cobalt doped PbTiO3 powder ceramics was carried out. X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Raman, and electron paramagnetic resonance (EPR) spectroscopies were applied along with nonsimultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The doped and undoped PbTiO3 materials were synthesized via a practical sol-gel route that takes place at 50 °C. The perovskite formation for both materials was verified. The dislocation density of cobalt doped PbTiO3 was found to be 0.0121 nm-2 while it was 0.00239 nm-2 for the undoped material. Besides, a strong strain effect was observed for cobalt doped PbTiO3 via XRD. This was attributed to the Co3O4 phase which was detected through EPR and FT-IR analyses. The formation of the Co3O4 phase during synthesis revealed the previously unexpected nonimproved ferroelectric behavior for cobalt doped PbTiO3. The dielectric constant and the dielectric loss (tan δ) of cobalt doped PbTiO3 were estimated as 1066 and 0.8370, respectively.