Dielectrophoresis model for the colossal electroresistance of phase-separated manganites

TL;DR

This paper introduces a dielectrophoresis model explaining how electric fields induce filament formation in phase-separated manganites, causing colossal electroresistance without changing the metallic phase fraction.

Contribution

It presents a novel dielectrophoresis-based mechanism for electroresistance, emphasizing cluster reconfiguration and filament formation under electric fields in manganites.

Findings

Electric fields cause metallic clusters to reconfigure into filaments.

Filament formation leads to insulator-metal transition without increasing metallic phase.

The process explains the colossal electroresistance observed in manganites.

Abstract

We propose a dielectrophoresis model for phase-separated manganites. Without increase of the fraction of metallic phase, an insulator-metal transition occurs when a uniform electric field applied across the system exceeds a threshold value. Driven by the dielectrophoretic force, the metallic clusters reconfigure themselves into stripes along the direction of electric field, leading to the filamentous percolation. This process, which is time-dependent, irreversible and anisotropic, is a probable origin of the colossal electroresistance in manganites.