Abstract
The heightened piezoelectric performance observed in most explored perovskite systems is typically at-tributed to the electric-field-induced phase transition near the morphotropic phase boundary(MPB)or polymorphic phase boundary(PPB).This study,however,unveils a distinct piezoelectric enhancement mechanism in the xPb(Nb2/3Ni1/3)O3-(1-x)Pb(Zr0.3Ti0.7)O3(PNN-PZT)system,diverging from the MPB/PPB-centered piezoelectric systems.Notably,the composition with x=0.55,positioned close to the tetragonal-pseudocubic(T-PC)phase boundary,achieves an unprecedented piezoelectric coefficient(d33)of 1264 pC/N,while retaining a tetragonal local structure.Importantly,on a local scale,electric fields do not in-cite phase transitions,suggesting that the exceptional piezoelectric performance in PNN-PZT stems from polarization extension near the T-PC boundary.Distinct from other mechanisms,the relative permittivity significantly increases post-poling due to this particular enhancement process.The dielectric behavior in poled specimens does not exhibit a conspicuous change at the ferroelectric-relaxor transition tempera-ture.However,both the relative permittivity and planar electromechanical coupling coefficient experience a sharp rise in the temperature range of-25 ℃ to 25 ℃.This investigation underscores the pivotal role of designing compositionally-driven T-PC phase boundaries,presenting a promising avenue for enhancing piezoelectric properties in ferroelectric ceramics.
基金项目
National Natural Science Foundation of China(11704301)
Natural Science Basic Research Plan in Shaanxi Province of China(2022JM212)
NETL
NSTL
万方数据