BaTiO3-(Bi1/2Na1/2)TiO3 solid-solution semiconducting ceramics with Tc>130°C -: art. no. 102104

As a candidate of a lead-free positive temperature coefficient of resistivity (PTCR) material, barium titanate (BaTiO3)-based solid-solution ceramics, Ba1-x(Bi1/2Na1/2)(x)TiO3 with x=0.05 (BBNT5), have been synthesized by an ordinary sintering technique. Temperature dependences of the dielectric and ferroelectric properties show ferroelectric and paraelectric phase transition of the ceramics with the Curie temperature of T-c = 170 degrees C, which is higher than that of BaTiO3 (130 degrees C). The La-doped BBNT5 ceramics display low rho values of 10(2)-10(3) Omega cm at room temperature and their abrupt changes of 10(2)-10(4) at about 220 degrees C. The reduced BBNT5 ceramics show small PTCR characteristics compared to the La-doped ones. (c) 2005 American Institute of Physics.