Nonlinear strain and DC bias induced piezoelectric behaviour of electrostrictive lead magnesium niobate-lead titanate ceramics under high electric fields

摘要

Laser Doppler interferometry has been used to determine the strain and piezoelectric response of Pb(M-Nb-1/3(2/3))O-3-PbTiO3 (PMN-PT) electrostrictive ceramics as a function of electric fields up to 4 MV m(-1), frequencies between 0.1 Hz and 2.5 kHz and DC bias fields up to 3 MV m(-1). The strain and polarization of PMN-15 with a composition of 0.9PMN-0.1PT and PMN-38 with a composition of 0.85PMN-0.15PT both produced by TRS ceramics, have been measured at room temperature. The strain and polarization responses of PMN-15 ceramics under an electric field up to 4 MV m(-1) have been fitted to a polynomial model. The results suggest C, Zn that a quadratic dependence of strain on polarization is not valid for large electric fields and that higher-order terms must be included. Our measurements showed that the effective piezoelectric coefficient, d(33), of PMN-15 ceramics had a maximum value of 800 pm V-1 at a bias field of 0.67 MV m(-1) and had little frequency dependence in the frequency range from 1 Hz up to 2.5 kHz. PMN-38 ceramic showed a maximum d(33) of 1200 pm V-1 at a bias field of 0.43 MV m(-1) and the d(33) of this material showed a clear frequency dependence from 1 HZ up to 2.5 kHz. [References: 12]