Frequency dependent polarisation switching in h-ErMnO$_3$

TL;DR

This study investigates the intrinsic dielectric behavior and frequency-dependent polarization switching in h-ErMnO$_3$, revealing domain-wall dynamics and saturation polarization, advancing potential applications in domain-wall electronics.

Contribution

It provides a detailed dielectric analysis of h-ErMnO$_3$, identifying intrinsic behavior regimes and elucidating domain-wall driven polarization switching mechanisms.

Findings

Identified temperature and frequency ranges for intrinsic dielectric behavior.

Measured ferroelectric hysteresis loops showing saturation polarization of 5-6 μC/cm$^2$.

Demonstrated frequency-dependent polarization switching linked to domain-wall movement.

Abstract

We report an electric-field poling study of the geometric-driven improper ferroelectric h-ErMnO$_3$. From a detailed dielectric analysis we deduce the temperature and frequency dependent range for which single-crystalline h-ErMnO$_3$ exhibits purely intrinsic dielectric behaviour, i.e., free from extrinsic so-called Maxwell-Wagner polarisations that arise, for example, from surface barrier layers. In this regime ferroelectric hysteresis loops as function of frequency, temperature and applied electric fields are measured revealing the theoretically predicted saturation polarisation in the order of 5 - 6 $\mu$C/cm$^2$. Special emphasis is put on frequency-dependent polarisation switching, which is explained in terms of domain-wall movement similar to proper ferroelectrics. Controlling the domain walls via electric fields brings us an important step closer to their utilization in domain-wall-based electronics.