Giant reversible nanoscale piezoresistance at room temperature in Sr2IrO4 thin films

TL;DR

This study demonstrates that nanoscale vertical compression can induce a five orders of magnitude change in resistivity of Sr2IrO4 thin films at room temperature, revealing giant reversible piezoresistance and potential for piezotronic applications.

Contribution

The paper reports the discovery of giant, reversible piezoresistance in Sr2IrO4 thin films induced by nanoscale compression at room temperature, a novel property for iridates.

Findings

Resistivity changes by five orders of magnitude under nanoscale compression.

Piezoresistance is fully reversible and significant at room temperature.

Iridates show promise for room temperature piezotronic devices.

Abstract

Layered iridates have been the subject of intense scrutiny on account of their unusually strong spin-orbit coupling, which opens up a narrow gap in a material that would otherwise be a metal. This insulating state is very sensitive to external perturbations. Here, we show that vertical compression at the nanoscale, delivered using the tip of a standard scanning probe microscope, is capable of inducing a five orders of magnitude change in the room temperature resistivity of Sr2IrO4. The extreme sensitivity of the electronic structure to anisotropic deformations opens up a new angle of interest on this material, and the giant and fully reversible perpendicular piezoresistance makes iridates a promising material for room temperature piezotronic devices.