Localized reversible nanoscale phase separation in Pr_0.63Ca_0.37MnO_3 single crystal using a scanning tunneling microscope tip

TL;DR

This study demonstrates reversible nanoscale phase separation in a manganite crystal by using a scanning tunneling microscope tip to locally manipulate electronic states, enabling high-resolution writing and erasing of metallic regions.

Contribution

It introduces a method for reversible, localized phase manipulation in a manganite crystal using STM, enabling nanoscale control of electronic phases.

Findings

Localized metallic nanoislands can be created and erased in the insulating matrix.

The process is reversible with current polarity reversal.

Metallic regions persist after current reduction, allowing stable phase separation.

Abstract

We report the destabilization of the charge ordered insulating (COI) state in a localized region of Pr_0.63Ca_0.37MnO_3 single crystal by current injection using a scanning tunneling microscope tip. This leads to controlled phase separation and formation of localized metallic nanoislands in the COI matrix which have been detected by local tunneling conductance mapping. The metallic regions thus created persist even after reducing the injected current to lower values. The original conductance state can be restored by injecting a current of similar magnitude but of opposite polarity. We thus achieve reversible nanoscale phase separation that gives rise to the possibility to "write, read, and erase" nanosized conducting regions in an insulating matrix with high spatial resolution.