First-order polarization process as an alternative to antiferroelectricity

TL;DR

This paper demonstrates that a first-order polarization process in strained CaTiO3 thin films can produce double-hysteresis P-E loops, offering an alternative to traditional antiferroelectric mechanisms.

Contribution

It introduces a novel first-order polarization process in non-polar CaTiO3, expanding the understanding of polarization switching phenomena.

Findings

Double-hysteresis P-E loops observed in CaTiO3 thin films under tensile strain.

Field-induced abrupt polarization rotation explains the double hysteresis.

First-order polarization process offers an alternative to antiferroelectricity for applications.

Abstract

Antiferroelectrics generate significant interest since their polarization versus electric field (PE) curves show typical double-hysteresis loops appealing for various applications. Unfortunately, antiferroelectrics are rare. In magnetic compounds, magnetization versus magnetic field (M-H) curves can show analogous double hysteresis loops not only in antiferromagnets but also in systems exhibiting field-induced first-order reorientation of the magnetization through a so-called first-order magnetization process. Here, we show that appealing double-hysteresis P-E loops can also appear from an unprecedented first-order polarization process. Focusing on non-polar CaTiO3, which can be turned ferroelectric under tensile strain, we study epitaxial thin films on differently-oriented NdGaO3 substrates using a combination of theoretical and experimental techniques. We uncover that a certain configuration exhibits double-hysteresis P-E loops that we rationalize from a field-induced abrupt rotation of the polarization. Such a first-order polarization process establishes a promising alternative pathway to achieve double hysterisis P-E loops appealing for practical applications.