A morphotropic phase boundary system based on polarization rotation and polarization extension

TL;DR

This paper proposes a temperature-composition phase diagram for ferroelectric materials that enables polarization rotation and extension, leading to enhanced properties with improved temperature stability.

Contribution

It introduces a novel phase diagram that combines polarization rotation and extension mechanisms for improved ferroelectric properties.

Findings

Phase diagram shows compositionally driven phase transitions.

Enhanced properties due to combined polarization mechanisms.

Improved temperature stability of ferroelectric enhancements.

Abstract

Many ferroelectric solid solutions exhibit enhanced electro-mechanical properties at the morphotropic boundary separating two phases with different orientations of polarization. The mechanism of properties enhancement is associated with easy paths for polarization rotation in anisotropically flattened free energy profile. Another mechanism of properties enhancement related to free energy flattening is polarization extension. It is best known at temperature-driven ferroelectric-paraelectric phase transitions and may lead to exceedingly large properties. Its disadvantage is temperature instability of the enhancement. In this paper a temperature-composition phase diagram is proposed that exhibits compositionally driven-phase transitions with easy paths for both polarization rotation and polarization extension.