Effect of polyethylene glycol on the microstructure and PTCR characteristics of n-BaTiO3 ceramics

Porous BaTiO₃ (n-BaTiO₃) ceramics doped donor were fabricated by the addition of polyethylene glycol (PEG) into the n-BaTiO₃ powder. The effects of PEG on the microstructure and PTCR characteristics of the porous n-BaTiO₃ ceramics have been investigated. An endotherm was found at 60 °C, with strong exotherm at 262 °C, weight loss commenced at 165 °C and was virtually complete by 265 °C from the differential thermal analysis (DTA) and thermogravimetric analysis (TGA) of the PEG. It was also found that the porosity increased and the grain size decreased with increasing PEG. The crystalline structure of n-BaTiO₃ ceramics was independent on the PEG content and the n-BaTiO₃ ceramics containing PEG showed the presence of (Ba, Sr)TiO₃ peaks only from the XRD results. The n-BaTiO₃ ceramics containing PEG showed higher PTCR characteristics than that of the n-BaTiO₃ ceramics without PEG.