TY - GEN
T1 - Complex impedance analyses of high Tc BaTiO3-based Pb-free PTCR ceramics
AU - Xiang, Ping Hua
AU - Tareda, Hiroaki
AU - Shiosaki, Tadashi
PY - 2007
Y1 - 2007
N2 - A distinct positive temperature coefficient of resistance (PTCR) effect has been observed in Bi0.5Na0.5TiO3 (BNT)-added BaTiO3 (BT) ceramics sintered in N2 flow with a low O 2 concentration . With the addition of 10 mol.% BNT, the samples exhibited resistivity jumps of above 103 at 189 °C. The BNT-added BT ceramics was also analyzed using an a.c. complex impedance spectroscopy to reveal the origin of the PTCR effect. An electrically inhomogeneous microstructure of the grain interiors, surface layers surrounding the gains and grain boundaries were deduced by the complex impedance analyses. The observed d.c. resistivity increase was mainly due to the increase in grain boundary resistivity. The surface layer appeared to slightly contribute to the PTCR effect in the BNT-added BT ceramics. The grain interior also exhibited a resistivity anomaly around Ts. But, the resistivity of gain interior decreased with temperature higher than Ts.
AB - A distinct positive temperature coefficient of resistance (PTCR) effect has been observed in Bi0.5Na0.5TiO3 (BNT)-added BaTiO3 (BT) ceramics sintered in N2 flow with a low O 2 concentration . With the addition of 10 mol.% BNT, the samples exhibited resistivity jumps of above 103 at 189 °C. The BNT-added BT ceramics was also analyzed using an a.c. complex impedance spectroscopy to reveal the origin of the PTCR effect. An electrically inhomogeneous microstructure of the grain interiors, surface layers surrounding the gains and grain boundaries were deduced by the complex impedance analyses. The observed d.c. resistivity increase was mainly due to the increase in grain boundary resistivity. The surface layer appeared to slightly contribute to the PTCR effect in the BNT-added BT ceramics. The grain interior also exhibited a resistivity anomaly around Ts. But, the resistivity of gain interior decreased with temperature higher than Ts.
UR - https://www.scopus.com/pages/publications/51349132786
U2 - 10.1109/ISAF.2007.4393411
DO - 10.1109/ISAF.2007.4393411
M3 - 会议稿件
AN - SCOPUS:51349132786
SN - 1424413338
SN - 9781424413331
T3 - IEEE International Symposium on Applications of Ferroelectrics
SP - 815
EP - 817
BT - 2007 16th IEEE International Symposium on the Applications of Ferroelectrics, ISAF
T2 - 2007 16th IEEE International Symposium on the Applications of Ferroelectrics, ISAF
Y2 - 27 May 2007 through 31 May 2007
ER -