Two different effective thresholds for the onset of nonlinearity in the dielectric and piezoelectric coefficients of donor-doped lead zirconate titanate (soft PZT) piezoceramics at electric ac fields Ec1≈100V/cm and Ec2≈1V/cm are found. Both are characterized by a scaling behavior x=x0+A[E-Ec)/Ec]F above the respective threshold, where x is the dielectric or piezoelectric coefficient. The values of the effective exponent are apparently independent of the particular ceramic system which suggests a universal behavior in soft PZT. We suggest that the nonlinearity is dominated by the dynamics of domain walls in a randomly pinned medium.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)