Electrical conductivity of the Bi-based lead-free piezoelectric ceramic BiFeO3

Bi-based lead-free piezo-ceramics such as BiFeO3 (BFO) have been studied intensively in attempts to replace PZT-based ceramics. However, some of those ceramics have resistivity causing difficulties in poling thus yielding poor piezoelectric properties. To improve proper-ties, it is necessary to have better understanding on the conduction mechanism and defect chemistry of those systems. In this work, BNT as a base system of Pb-free ceramics and BiFeO3 (BF) as one of multiferroic ceramics were prepared via a typical solid state reaction method. Electrical conductivity of each system was measured using 4-probe method at the oxygen partial pressures range from 100 to 10??5 atm and temperature range of 500~800??????.