A structural perspective on the origin of the anomalous weak-field piezoelectric response at the polymorphic phase boundaries of (Ba, Ca)(Ti, M)O3 lead-free piezoelectrics

摘要

In this paper, we compare the structural features of Ca modified Ba(Ti, Sn)O3with that of its Ca-free counterpart to understand why the Ca-modified variantof this lead-free piezoelectric gives a much higher piezoelectric response. Wefound that in spite of the reduced spontaneous lattice strain, the polarizationof the Ca-modified variant is higher. We, therefore, demonstrate that the verylarge piezoelectric response of (Ba, Ca)(Ti, Sn)O3 is associated with thedecoupling of the polarization and lattice strain by Ca-modification.