Effect of donor concentration on the PTCR behavior of Y-doped BaTiO-(BiNa)TiO ceramics.

Leng, Senlin; Li, Guorong; Zheng, Liaoying; Shi, Wei; Zhu, Ya

Lead-free positive temperature coefficient of resistivity (PTCR) ceramics of 99 mol%BaTiO-1 mol%(BiNa)TiO (BBNT1) and 90 mol%BaTiO-10 mol%(BiNa)TiO (BBNT10) were prepared by the conventional solid state reaction method. The effect of donor concentration on the microstructure and PTCR behavior of the BBNT ceramics were investigated. The results show that all BBNT1 and BBNT10 ceramics have formed a single perovskite structure with tetragonal phase when sintered in air or N. 0.2 mol% Y-doped BBNT1, sintered at 1,330 °C for 30 min in air, has room-temperature resistivity (ρ) of ~60 Ω cm and resistivity jump [maximum resistivity (ρ)/minimum resistivity (ρ)] of ~4.2 orders of magnitude with T about 150 °C. 0.4 mol% Y-doped BBNT10, sintered at 1,250 °C for 3 h in N, has ρ of ~100 Ω cm and resistivity jump of ~4.7 orders of magnitude with T about 180 °C. The BBNT10 has higher breakdown voltage of 200 V/mm (a.c.) than that of BBNT1, making these BBNT10 ceramics promising candidates for high temperature lead-free PTCR materials.

ELECTRICAL resistivity; ELECTRIC properties of barium titanate; PIEZOELECTRIC ceramics; MICROSTRUCTURE; LEAD-free ceramics

Journal of Materials Science: Materials in Electronics, 2013, Vol 24, Issue 1, p431

0957-4522

Academic Journal

10.1007/s10854-012-0774-x