Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films

TL;DR

This study uses conductive atomic force microscopy to observe how point defect disorder causes electronic inhomogeneities in manganite films, affecting their metal-insulator transition and magnetic properties.

Contribution

It provides direct real-time imaging of electronic inhomogeneities caused by point defects in manganite films, linking disorder to changes in electronic and magnetic behavior.

Findings

Electronic inhomogeneities increase with disorder

Metal-insulator transition shifts to lower temperatures with more defects

Saturation magnetization decreases as irradiation dose increases

Abstract

We have investigated the influence of point defect disorder in the electronic properties of manganite films. Real-time mapping of ion irradiated samples conductivity was performed though conductive atomic force microscopy (CAFM). CAFM images show electronic inhomogeneities in the samples with different physical properties due to spatial fluctuations in the point defect distribution. As disorder increases, the distance between conducting regions increases and the metal-insulator transition shifts to lower temperatures. Transport properties in these systems can be interpreted in terms of a percolative model. The samples saturation magnetization decreases as the irradiation dose increases whereas the Curie temperature remains unchanged.