Evidence for Incipient Ferroelectricity in YCrO3

TL;DR

This paper investigates the incipient ferroelectric behavior of YCrO3, revealing a competition between octahedral rotations and Y atom displacement that influences its ferroelectric state, and suggests pathways to stabilize ferroelectricity.

Contribution

It demonstrates the competing effects in YCrO3 that lead to incipient ferroelectricity and proposes cation substitution as a method to enhance ferroelectric stability.

Findings

YCrO3 exhibits incipient ferroelectricity due to competing structural phenomena.

Octahedral rotations favor lower symmetry, opposing Y atom displacement.

Cation substitution at Y site could stabilize ferroelectricity.

Abstract

Cubic structure is one of the most commonly found structures for oxides at high temperature. As the temperature is lowered only a handful of these oxides exhibit ferroelectricity which is rather surprising. In this paper, we use the example of YCrO3 (YCO), an incipient ferroelectric material to show that in most oxides there are two competing phenomenon -onset of ferroelectricity due to rotation of CrO6 octahedra and displacement of Y atom leading to suppression of ferroelectricity. This competition reveals that while the octahedral rotations favor a lower symmetry state, the Y atom displacement opposes it leaving YCO to exhibit only an incipient ferroelectric state. These results while being in agreement with the earlier theoretical predictions can also help suggest a pathway to a more stable ferroelectric state in these oxides by using a larger cationic substitution at the Y site.