Effects of different bismuth-based compounds additives on the positive temperature coefficient effect of BaTiO3 ceramics

Synthesis and electrical properties of BaBiO3 and high resistivity BaTiO3–BaBiO3 ceramics

“…14 While doped BB has been studied primarily for superconductor applications as mentioned above, BaBiO 3 -doped BaTiO 3 (BT-BB) solid solutions have been studied by some researchers for use as positive temperature coefficient of resistivity (PTCR) devices. 15,16 In one study, it was shown that addition of BB increased the Curie point so that the PTCR effect was initiated above $150 C. 17 This report is focused on BT-BB solid solutions for the purpose of understanding the influence of BB additions on the electrical properties of BT. It has been demonstrated that small concentration of BB were enough to increase the resistivity of BT-BB solid solutions by several orders of magnitude, suggesting a drastic change in underlying defect chemistry.…”

Effect of Na2Ti6O13 addition on the microstructure and PTCR characteristics of Ba0.94(Bi0.5K0.5)0.06TiO3 ceramics

“…Therefore, incorporation of the KBT phase into the semiconducting BT-based ceramics is considered an effective way to increase the T C to a higher temperature. Yuan et al [8] reported that when the content of KBT was above 3% in the BaTiO 3 -Bi 0.5 K 0.5 TiO 3 system ceramics, it was hard to obtain low room temperature resistivity after sintering in air.…”