Aging of piezoelectric properties in Pb(MgNb)O3-Pb(ZrTi)O3 multilayer ceramic actuators

Aging characteristics of 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) multilayer ceramic actuators have been investigated by applying rectified ac bias. Multilayer ceramic actuators 5x5x5 mm3 in size were fabricated by tape-casting methods. X-ray diffraction analyses were performed to compare crystalline structures and lattice parameters. Effective electromechanical coupling coefficient keff and pseudopiezoelectric constant d33 were calculated and discussed. Different rectified ac electric biases were applied to the actuators to investigate aging behavior in the multilayer ceramic actuators. The aging dependencies of cycles and electric fields were simulated and fitted to the linear logarithmic stretched exponential law