Introduction Motivation Problems in relaxors: 1.Polarization rotation induced piezoelectricity enhancement? 2.Ferroelectric nanoclusters induced piezoelectricity enhancement? Introduction & Motivation Problems in relaxors: 1.Polarization rotation induced Polarization rotation induced piezoelectricity enhancement? piezoelectricity enhancement? 2.Ferroelectric Ferroelectric nanoclusters nanoclusters induced induced piezoelectricity enhancement? piezoelectricity enhancement?