Controllable anisotropic characteristics in solid solution ferroelectrics

Abstract

Composition gradient (CG) has significant influences on the polarization states by providing flexoelectric and gradient energy, which induces anisotropic macroscopic properties. In this work we have designed and grown KTa_1−xNb_xO₃ (KTN) single crystals with anisotropic CGs. The results reveal that the anisotropic CGs induce anisotropic properties, the larger CG corresponds to the smaller dielectric permittivity, and more ordered and preferred orientation of spontaneous polarization. Besides, by increasing the CG of KTN single crystals, internal fields (E_in) will be generated, which is the origin of the polarization orientation and order degree along the E_in direction. In addition, results also show that the anisotropic CGs of KTN are controllable, which provides a potential alternative way to control the anisotropic characteristics of KTN.