Ferroelectricity of Li-doped silver niobate (Ag,Li)NbO3

TL;DR

This study investigates how lithium doping induces ferroelectricity in silver niobate, revealing structural transformations and enhanced polarization with increased Li content, which could improve ferroelectric material applications.

Contribution

It demonstrates that Li substitution causes a structural phase change and increases ferroelectric polarization in AgNbO3, providing new insights into doping-induced ferroelectricity.

Findings

Li doping induces orthorhombic to rhombohedral phase transition.

Increased Li enhances ferroelectric polarization.

Li doping raises the para-ferroelectric transition temperature.

Abstract

Phase evolution in (Ag1-xLix)NbO3 (ALN) solid solution was investigated by X-ray diffraction technique, dielectric and polarization measurements. It is shown that small substitution of Ag with Li gives rise to an orthorhombic-rhombohedral structural transformation in ABO3-perovskite silver niobate at room temperature. Structural refinements indicate that both A- and B-site displacements contribute to the spontaneous polarization of the ferroelectric phase with symmetry R3c. Increasing Li-concentration enhances the ferroelectric rhombohedral distortion, resulting in the increase of the para-ferroelectric phase transition temperature and the polarization of the solid solutions.