Switchable tribology of ferroelectrics

TL;DR

This paper demonstrates that ferroelectric materials exhibit switchable, polarization-dependent tribological properties, enabling nanoscale patterning and potential large-scale applications through electrically tunable wear behaviors.

Contribution

It reveals universal, polarization-sensitive tribological asymmetry in ferroelectrics and introduces a method for 3D nanostructuring using domain-based smart masks.

Findings

Down domains have lower friction and wear rates than up domains.

The tribological asymmetry is universal across different ferroelectrics.

Demonstrated scalable 3D nanostructuring using domain-based patterning.

Abstract

Artificially induced asymmetric tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe where down domains having lower friction coefficient than up domains can be used as smart masks as they show slower wear rate than up domains. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is universal across ferroelectrics with different chemical composition and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm-cm) size. These findings establish that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.