Explanation of Giant Cluster Coexistence in Doped Manganites and Other Compounds

TL;DR

This paper explains the coexistence of large metallic and insulating clusters in doped manganites through computational models, linking disorder effects to experimental observations of inhomogeneities.

Contribution

It introduces a model-based explanation for cluster coexistence in manganites, emphasizing the role of disorder and percolation phenomena, and extends the understanding to other compounds.

Findings

Large coexisting clusters are induced by disorder near first-order transitions.

The random-field Ising model qualitatively explains the cluster formation.

Results account for micrometer-scale inhomogeneities observed experimentally.

Abstract

Computational studies show the generation of large coexisting metallic and insulating clusters with equal electronic density in models for manganites. The clusters are induced by disorder on exchange and hopping amplitudes near first-order transitions of the non-disordered strongly coupled system. The random-field Ising model is used to explain the qualitative aspects of our results. Percolative characteristics are natural in this context. Our results explain the recently experimentally discovered micrometer size inhomogeneities in manganites. The conclusions are general and apply to a variety of compounds.