The PTCR Performance of Nb-Doped BaTiO3-NBT Ceramics
In this paper, Nb-doped BaTiO3-(Na0.5Bi0.5)TiO3 (BBNT-Nb) based PTCR ceramic material has been prepared using high purity Nb2O5, Bi2O3, Na2CO3, TiO2 and BaTiO3 powders as starting materials, and its structural and electrical properties are investigated. The results indicated that the Nb2O5 dopant is helpful not only to promote the formation of tetragonal BBNT structure without any second phase, but also to decrease the room-temperature resistivity. For the 0.10at% Nb-doped BBNT material with BNT content 35mol%, the properties of room-temperature resistance of 104Ω·cm, temperature coefficient (αk) of 6.3%/°C, PTCR anomaly lg(Rmax/Rmin) of 3.6 and Curie temperature (Tc) of 193°C are obtained.
Jianzhong Wang and Jingang Qi
L. Z. Li et al., "The PTCR Performance of Nb-Doped BaTiO3-NBT Ceramics", Advanced Materials Research, Vols. 299-300, pp. 512-515, 2011