High density array of epitaxial BiFeO3 nanodots with robust and reversibly switchable topological domain states

TL;DR

This paper reports the creation of high-density arrays of epitaxial BiFeO3 nanodots with stable, reversible topological domain states, advancing nanoelectronic device potential through controlled nanoscale ferroelectric structures.

Contribution

It introduces a method to fabricate dense arrays of epitaxial BiFeO3 nanodots with switchable topological domains, enabling individual addressability for nanoferroelectric applications.

Findings

Stable topological domain structures in nanodots demonstrated.

Reversible switching of domain states by electric field achieved.

Formation mechanisms linked to surface charge accumulation elucidated.

Abstract

The exotic topological domains in ferroelectrics and multiferroics have attracted extensive interest in recent years due to their novel functionalities and potential applications in nanoelectronic devices. One of the key challenges for such applications is a realization of robust yet reversibly switchable nanoscale topological domain states with high density, wherein spontaneous topological structures can be individually addressed and controlled. This has been accomplished in our work using high density arrays of epitaxial BiFeO3 (BFO) nanodots with lateral size as small as ~60 nm. We demonstrate various types of spontaneous topological domain structures, including center-convergent domains, center-divergent domains, and double-center domains, which are stable over sufficiently long time yet can be manipulated and reversibly switched by electric field. The formation mechanisms of these topological domain states, assisted by the accumulation of compensating charges on the surface, have also been revealed. These result demonstrated that these reversibly switchable topological domain arrays are promising for applications in high density nanoferroelectric devices such as nonvolatile memories