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 60degreesC, with strong exotherm at 262degreesC, weight loss commenced at 165degreesC and was virtually complete by 265degreesC 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. (C) 2004 Elsevier Ltd and Techna S.r.l. All rights reserved.