Harmonic analysis of the polarization response in Pb(Mg1/3Nb2/3)O3-based ceramics-A study inaging

摘要

The polarization response of a ferroelectric ceramic displaysnnonlinear behavior at high applied fields due to saturation effects.nWeak-field dielectric aging imposes additional nonlinearity on thenhysteresis loops of these materials. Harmonic analysis using a discretenFourier transform (DFT) permitted an observation of the change in thenpolarization frequency spectrum as Pb(Mg1/3Nb2/3)On3-based relaxor ceramics aged. It also facilitated thencalculation of ac current, power, and “internal bias field”.nThe results show that particular harmonics in the polarization signalnare sensitive indications of aging behavior. The average powerndissipated at weak ac fields was found to decrease with aging time; andnthe power dissipated at strong fields tended to increase